26 results on '"Mahanta SK"'
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2. IG 96-50 (IC0630758; INGR19062), a Buffel grass (Cenchrus ciliaris) Germplasm with High Water Soluble Carbohydrate. Good for Silage Preparation. Leaf Colour Pale-Low Chlorophyll Content
- Author
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Singh, S, Singh, T, Singh, KK, Das, MM, Srivastava, MK, Mahanta, SK, Misra, AK, Katiyar, R, and Ghosh, PK
- Published
- 2021
3. IG 96-96 (IC0630759; INGR19063), a Buffel grass (Cenchrus ciliaris) Germplasm with High Water Soluble Carbohydrate. Good for Silage Preparation.
- Author
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Singh, S, Singh, T, Singh, KK, Das, MM, Srivastava, MK, Mahanta, SK, Misra, AK, Katiyar, R, and Ghosh, PK
- Published
- 2021
4. Assessment of genetic diversity in Sehima nervosum for yield, nutritional traits and ensiling quality.
- Author
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Singh S, Singh T, Kumar N, Koli P, Das MM, Mahanta SK, Singh KK, Jha PK, Prasad PV, Srivastava MK, and Katiyar R
- Abstract
The low sugar content of tropical range grasses makes them difficult to ensiling. This study identified sugar rich (>7 % on dry matter basis) accessions of Sehima nervosum ( SN ), which is adequate to initiate lactic acid production during ensiling. Sehima is a prominent range grass of Sehima-Dichatnthium grasslands in India followed by Africa, Pakistan, China and Australia. In this study, 92 diverse SN germplasm accessions were evaluated for biomass yield, nutritional quality and sugar content. Green forage yield was higher in rainy season (ranged 2.2 to 58.1 t ha
-1 ) compared to post rainy season (varied between 0.48 and 44.0 t ha-1 ). The approximates values expressed (%), crude protein ranged from 3.15 to 6.10, neutral detergent fiber from 67.13 to 81.95, acid detergent fiber from 42.03 to 56.05, cellulose from 24.49 to 37.98 and lignin from 3.78 to 7.97. Sugar content varied from 27.04 to 123.32 mg g-1 DM. To advance this experiment, the next phase involved selecting 19 accessions of SN with >7 % sugar content on DM and promising forage yield. These accessions again evaluated for nutritional quality, subjected to in vitro tests, and then assessed for ensiling potential. Among 19 accessions, carbohydrate bound to lignin ( Cc ) ranged from 15.35 % to 25.63 % total carbohydrates. The total digestible nutrients (TDN) ranged from 33.07 % to 44.32 %, digestible energy (DE) from 1.46 to 1.95 Kcal per kg of dry matter (DM), and metabolizable energy (ME) from 1.20 to 1.60 Kcal per kg of DM. The intake of dry matter, digestible dry matter, and relative feed value varied from 1.55 to 1.77, 45.88 %-51.51 %, and 57.96 %-66.94 %, respectively. Methane production, as a percentage of the total gas, was at its lowest for IG-99-195 (7.91 %) and reached its highest for IG-01-391 (14.97 %). Silage pH ranged from 4.57 (IG-02-703) to 5.61 (IG-99-181) and lactic acid from 0.094 % to 1.774 % DM. Accessions IG-02-703, IG-02-713, and IG-2045-1 had good silage quality, with suitable pH and lactic acid levels. Planting these in pastures and grazing lands could improve the availability of quality fodder during lean periods., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025 The Authors.)- Published
- 2025
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5. Assessing genotypes of buffel grass (Cenchrus ciliaris) as an alternative to maize silage for sheep nutrition.
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Singh S, Koli P, Singh T, Das MM, Maity SB, Singh KK, Katiyar R, Misra AK, Mahanta SK, Srivastava MK, Anele UY, Oderinwale OA, and Ren Y
- Subjects
- Animals, Sheep, Animal Nutritional Physiological Phenomena, Female, Animal Feed analysis, Digestion, Silage analysis, Zea mays genetics, Zea mays chemistry, Genotype, Nutritive Value, Cenchrus genetics, Cenchrus metabolism
- Abstract
Nutritive value of five Cenchrus ciliaris (buffel grass) genotypes (IG96-50, IG96-96, IG96-358, IG96-401 and IG96-403) weredetermined. Their sugar contents (>70 mg/g of dry matter) and ensiling potential were evaluated using in vitro batch culture and in vivo studies. Research indicated significant differences (P < 0.05) in the dry matter, organic matter, ether extract, neutral detergent fiber, acid detergent fiber, cellulose and lignin contents of the C. ciliaris genotypes tested. Genotypes also differed (P < 0.05) in total carbohydrates, structural carbohydrates, non-structural carbohydrates and protein fractions. Genotype IG96-96 had the lowest total digestible nutrients, digestible energy and metabolizable energy contents (377.2 g/kg, 6.95 and 5.71 MJ/kg of dry matter, respectively), and net energy values for lactation, maintenance and growth. After 45 days of ensiling, C. ciliaris silages differed (P < 0.05) in dry matter, pH, and lactic acid contents, and their values ranged between 255-339, 4.06-5.17 g/kg of dry matter and 10.8-28.0 g/kg of dry matter, respectively. Maize silage had higher (P < 0.05) Organic Matter (919.5g/kg of dry matter), ether extract (20.4g/kg of dry matter) and hemi-cellulose (272.3 g/kg of dry matter) than IG96-401 and IG96-96 silages. The total carbohydrates and non-structural carbohydrates of maize silage were higher (P < 0.05), while structural carbohydrates were comparable (P < 0.05) with C. ciliaris silages. Sheep on maize silage had (P < 0.05) higher metabolizable energy, lower crude protein, and digestible crude protein intake (g/kg of dry matter) than those on C. ciliaris silage diets. Nitrogen intake and urinary-N excretion were higher (P < 0.05) on genotype IG96-96 silage diet. Overall, this study suggested that certain C. ciliaris genotypes, notably IG96-401 and IG96-96, exhibited nutritive values comparable to maize silage in sheep studies, offering a promising avenue for future exploration as potential alternatives in diversified and sustainable livestock nutrition programs., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)
- Published
- 2024
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6. Periodontal Lesions among Maxillary Sinus Mucosal Thickening Visiting the Department of Oral Medicine and Radiology of a Tertiary Care Centre.
- Author
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Bali H, Neupane M, Mahanta SK, Niroula D, Upadhyaya C, and Kafle D
- Subjects
- Male, Humans, Adult, Middle Aged, Aged, Female, Cross-Sectional Studies, Tertiary Care Centers, Cone-Beam Computed Tomography methods, Maxillary Sinus diagnostic imaging, Maxillary Sinus pathology, Radiology
- Abstract
Introduction: Maxillary sinus due to its proximity to posterior maxillary teeth could be affected by their pathology. Since cone beam computed tomography is the go-to for 3-D imaging in dental set-up. This study aimed to find out the prevalence of periodontal lesions among maxillary sinus mucosal thickening visiting the Department of Oral Medicine and Radiology of a tertiary care centre., Methods: This descriptive cross-sectional study was conducted in the Department of Oral Medicine and Radiology of a tertiary care centre from 01 February 2021 to 30 June 2021 after obtaining ethical approval from the Institutional Review Committee. The medical records from 01 January 2019 to 31 December 2019 were retrieved. The identification of maxillary sinus mucosal thickening of more than 3 mm, in cone beam computed tomography images, was registered separately for the right and left sinuses of each patient. The presence of periodontal lesions of posterior teeth was recorded. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval., Results: Among 195 maxillary sinus mucosal thickening, periodontal lesions were found in 74 (37.95%) (31.14-44.76, 95% Confidence Interval) maxillary sinuses of 46 patients. The mean age was 53.67±12.72 years and 30 (65.21%) were males., Conclusions: The prevalence of periodontal lesions among maxillary sinus mucosal thickening in CBCT images was similar to other studies done in similar settings., Keywords: cone beam computed tomography; maxillary sinus; periodontal disease; prevalence.
- Published
- 2024
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7. Dental Caries on Deciduous Molars among Children Visiting Dental Outpatient Department of a Tertiary Care Centre.
- Author
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Adhikari BR, Shakya M, Bhatta N, Upadhya S, and Mahanta SK
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- Infant, Child, Humans, Tertiary Care Centers, Cross-Sectional Studies, Molar, Outpatients, Dental Caries epidemiology
- Abstract
Introduction: Dental caries is one of the most common, yet preventable childhood diseases. The aetiology of dental caries lies in the interplay between host, microorganism, substrate, and time. Risk factors for dental caries include physical, biological, environmental, behavioural, and lifestyle-related factors such as high numbers of cariogenic bacteria, inadequate salivary flow, insufficient fluoride exposure, poor oral hygiene, inappropriate methods of feeding infants, and poverty. The aim of the study was to find out the prevalence of dental caries on deciduous molars among children visiting dental Outpatient Department of a tertiary care centre., Methods: This descriptive cross-sectional study was conducted on children who visited the dental outpatient department of Kathmandu University School of Medical Sciences, Dhulikhel Hospital from 15 June 2023 to 30 July 2023. Ethical approval was taken from the Institutional Review Committee of the same institute. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval., Results: The prevalence of dental caries on deciduous molars in children was 252 (93.33%)(90.35-96.30, 95% Confidence Interval). One-third of the children had visited dental clinics for the first time. Lack of topical fluoride application was seen in the majority of the children., Conclusions: The prevalence of dental caries on deciduous molars among pediatric patients was found to be higher than in other studies done in similar settings., Keywords: children; dental caries; molars; prevalence.
- Published
- 2023
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8. Evaluation of global Cenchrus germplasm for key nutritional and silage quality traits.
- Author
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Singh S, Singh T, Singh KK, Srivastava MK, Das MM, Mahanta SK, Kumar N, Katiyar R, Ghosh PK, and Misra AK
- Abstract
Cenchrus is important genera of grasses inhabiting tropical pastures and the Indian grasslands system. Its forage value is well established to sustain nomadic livestock and wildlife. This study deals with the evaluation of the representative set of global Cenchrus germplasm collection with 79 accessions belonging to six species ( C. ciliaris, C. setigerus, C. echinatus, C. myosuroides, C. pennisetiformis, and C. biflorus) at flowering stage. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose, and lignin values were in the range of 61.1-136, 640-749, 373-490, 277-375, and 35.6-75.50 g kg
-1 DM, respectively, while sugar contents varied from 11.6 to 101 mg g-1 DM. From the evaluated germplasm, 14 accessions of C. ciliaris having >70 mg g-1 DM sugar contents were selected and further evaluated for protein, fiber, carbohydrate and protein fractions, palatability indices, in vitro CH4 production, and ensiling traits. Protein contents were lower in EC397323 (61.8) and higher in IG96-96 (91.5), while the NDF, ADF, cellulose, and lignin contents varied between 678-783, 446-528, 331-405, and 39.6-62.0 g kg-1 DM, respectively. The carbohydrate and protein fractions of selected accessions differed ( p < 0.05), and the sugar contents varied ( p < 0.05) between 74.6 and 89.6 mg-1 g DM. Dry matter intake (DMI) and relative feed value (RFV) of accessions varied ( p < 0.05) and were in the range of 1.53-1.77% and 58.2-73.8 g kg-1 DM, respectively. The total digestible nutrients (TDNs), digestible energy (DE), and metabolizable energy (ME) of selected accessions varied between 362-487 g kg-1 DM, 6.62-8.90, and 5.42-7.29 Mj kg-1 DM, respectively. In vitro gas and CH4 production (24 h) varied ( p < 0.05) between 73.1 to 146 and 7.72 to 21.5 ml/g, respectively, while the degraded dry matter (g kg-1 DM) and CH4 (ml/g DDM) ranged between 399-579 and 17.4-47.2, respectively. The DM contents at ensiling, silage pH, and lactic acid contents of accessions differed ( p < 0.05) and ranged between 185-345 g kg-1 DM, 5.10-6.05, and 1.39-23.3 g kg-1 DM, respectively. Wide genetic diversity existed in germplasm and selected C. ciliaris accessions for protein fiber, energy, sugar, and other nutritional traits. Silage prepared from EC397366, IG96-96, IG96-50, and EC397323 had pH and lactic acid contents acceptable for moderate to good quality silage of tropical range grasses., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Singh, Singh, Singh, Srivastava, Das, Mahanta, Kumar, Katiyar, Ghosh and Misra.)- Published
- 2023
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9. Emergence Time and Sequence of Primary Teeth in a Sample of Nepalese Children.
- Author
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Upadhyay S, Deoju R, Mahanta SK, and Shrestha R
- Subjects
- Male, Female, Humans, Child, Infant, Child, Preschool, Cross-Sectional Studies, Nepal epidemiology, Tooth, Deciduous, Tooth Eruption, Incisor
- Abstract
Background Primary teeth emergence is an important milestone in children and timing of emergence varies among populations. Objective To determine the emergence time and sequence of primary teeth in a sample of Nepalese children visiting Dhulikhel Hospital. Method A descriptive cross-sectional study was conducted in children of 5 months to 4 years visiting Dhulikhel Hospital. The emergence of incisal tip to incisal margin for incisors and canines, cusp tip to occlusal margin of molars visible were recorded along with age in months and gender. Descriptive statistics was done to calculate the mean age of emergence of each tooth with standard deviation. Unpaired t-test was used to assess the difference between the mean age of emergence of teeth between right and left sides and between boys and girls. Result The first teeth to emerge was mandibular central incisor at the age of 9.37 ± 1.42 months and the last one was maxillary second molar at the age of 32.91 ± 6.39 months. There was no significant difference in the mean emergence time between the maxillary and mandibular jaws, between right and left sides of jaws and between boys and girls except for primary maxillary right central incisor and mandibular right second molar which was found to be emerged early in girls. Conclusion The emergence time and sequence of primary teeth observed in the present study can be used as a baseline data for the children of Kavre district.
- Published
- 2022
10. Oral Health Care Practice and Circumstances during Covid-19 among Dental Patients in Tertiary Care Hospital in Nepal.
- Author
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Prajapati D, Hada B, Ghimire G, Kc S, Singh S, Makaju S, and Mahanta SK
- Subjects
- Humans, Adolescent, Young Adult, Adult, Middle Aged, Aged, Tertiary Care Centers, Cross-Sectional Studies, Nepal epidemiology, Health Knowledge, Attitudes, Practice, Oral Health, COVID-19
- Abstract
Background Patients are hesitant to enter a dental hospital because of the significant danger of cross infection and illness transmission due to rapid spread of corona virus. Objective To assess knowledge regarding Covid-19, oral health practices and circumstances on dental treatment during a pandemic. Method Cross sectional study was conducted among patients visiting dental department of Dhulikhel hospital from September to October 2020. Questionnaires were interviewed following safety protocols regarding the pandemic and descriptive analysis was performed. Both verbal and written consent as well as ethical approval was taken before the study. Result A total 411 patients aged 14 to 75 years old from 14 different districts across Nepal participated in the study. All of the patient were free of Covid-19 symptoms and had strong knowledge and awareness about disease transmission. During the crisis 96% of the people maintain good oral hygiene while 25.8% acquire new dental problems where majority experienced oral discomfort and swelling, 93.2% of them did not attend a dental clinic or hospital in the interim owing to fear and inaccessibility. Majority of the participants were impressed by the safety precautions and preparations during treatment and 99.3% strongly suggest or pledge to visit dental department if necessary during the pandemic. Conclusion Dental patient visiting Dhulikhel hospital is highly aware of current health crisis, possible transmission and preventive measures. Proper safe hospital setup can encourage them to seek dental treatment during crisis. Dental pain and swelling in Endodontic department recorded most common dental emergency during this pandemic.
- Published
- 2022
11. Assessment of Palatal Throat Form in Lateral Cephalogram and its Correlation with the Skeletal Base and Facial Divergence: An Institutional Based Study.
- Author
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Sapkota B, Koju S, Mahanta SK, and Rimal U
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- Humans, Female, Male, Adolescent, Young Adult, Adult, Cephalometry methods, Palate diagnostic imaging, Maxilla diagnostic imaging, Pharynx diagnostic imaging, Malocclusion
- Abstract
Background Along with peripheral seal, palatal throat form also has significant value to achieve good retention and stability of maxillary complete denture. The palatal throat form also determines the posterior extention of maxillary dentures and affects the comfortability of the patients. Objective To analyse the palatal throat form in a Nepalese population based on age, gender malocclusion and facial divergence. Method This study consisted of 300 randomly selected radiographs with a mean age of 21.46±5.62 years. Skeletal malocclusion in lateral palatal throat form outlines. Patient were also categorized according to different Schudy's facial divergence angle (SNMP). The obtained data was tabulated based on the age, gender, palatal throat form, type of malocclusion and facial divergence. The results obtained were subjected to a statistical analysis to find the relation between variants of the soft palate and types of malocclusion in different gender groups. Result Proportion between palatal throat form and malocclusion found to be significant. There is no significant difference in proportion of different class of palatal throat form between genders. Whereas Class II palatal throat form found to be most common in all facial divergence. Conclusion It was observed that Class II malocclusion was most common among three types. The relation between palatal throat form and malocclusion, was found to be statistically significant.
- Published
- 2021
12. Digital Radiographic Study of Gonial angle in Forensic Odontology in a Tertiary Care Centre: A Descriptive Cross-sectional Study.
- Author
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Srii R, Koju S, Mahanta SK, Marla V, Niroula D, Upadhyaya C, and Murthy PS
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- Cephalometry, Cross-Sectional Studies, Female, Humans, Male, Radiography, Panoramic, Tertiary Care Centers, Mandible
- Abstract
Introduction: Gonial angle measurements serve as an important parameter of the craniofacial complex and are usually studied on lateral cephalograms, but recently panoramic radiographs have also been used. The aim of this study is to measure the gonial angle using orthopantomogram and lateral cephalogram based on age, gender, ethnicity, and skeletal malocclusion in a tertiary care hospital., Methods: This is a descriptive cross-sectional study comprising 350 selected radiographs of apparently healthy individuals collected for a period of one year, from the Department of Oral Radiology of a tertiary care centre of Nepal. Gonial angle measurements were recorded from digital panoramic radiograph (both right and left side) and lateral cephalogram. Data was collected in terms of age, gender, ethnicity, and skeletal malocclusion and then statistically analysed using the Statistical Package for the Social Sciences version 20., Results: The mean gonial angle for panoramic right, left and lateral cephalogram was 122.490±7.570, 123.620±7.060, and 124.150±6.910, respectively. There was a decrease in the mean values of the gonial angle observed as age advances seen in all the radiographs. The gonial angle measured in Class III malocclusion was higher in all the radiographs, followed by Class II and Class I. Gonial angles obtained in females were higher than the males in all the radiographs. Finally, the Aryan population showed a higher gonial angle compared to the Mongolian population in all the radiographs., Conclusions: Panoramic radiograph (left side), could be considered as a reliable tool to measure the gonial angle.
- Published
- 2021
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13. Visible-light driven Gd2Ti2O7/GdCrO3 composite for hydrogen evolution.
- Author
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Parida KM, Nashim A, and Mahanta SK
- Abstract
A series of Gd(2)Ti(2)O(7)/GdCrO(3) composites are prepared by solid state combustion method using Gd(NO(3))(3), TiO(2), Cr(2)O(3) as metal source and urea as a fuel. The composites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible diffuse reflectance spectra (DRUV-vis), Brunauer-Emmett-Teller (BET) surface area measurements, photoluminescence spectra (PL), X-ray photoelectron spectroscopic (XPS) studies, photocurrent measurements etc. The photocatalytic activity of the composites is examined towards hydrogen production without using any co-catalyst under visible light illumination. The rate of formation of hydrogen is measured by the photocatalytic activity measurement device and gas chromatography (GC). The highest efficiency is observed over the composite GTC (Cr:Gd:Ti = 1:1:1). On the basis of photocurrent measurements and PL, a mechanism for the enhanced photocatalytic activity has been discussed., (This journal is © The Royal Society of Chemistry 2011)
- Published
- 2011
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14. MUC1* is a determinant of trastuzumab (Herceptin) resistance in breast cancer cells.
- Author
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Fessler SP, Wotkowicz MT, Mahanta SK, and Bamdad C
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- Antibodies, Monoclonal, Humanized, Breast Neoplasms drug therapy, Breast Neoplasms genetics, Breast Neoplasms metabolism, Cell Line, Tumor drug effects, Cell Line, Tumor metabolism, Cyclophosphamide pharmacology, Dimerization, Doxorubicin pharmacology, Drug Resistance, Multiple drug effects, Drug Resistance, Neoplasm drug effects, Female, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Humans, Immunoglobulin Fab Fragments pharmacology, Mucin-1 chemistry, Mucin-1 genetics, Mucin-1 immunology, Neoplasm Proteins chemistry, Neoplasm Proteins genetics, Neoplasm Proteins immunology, Paclitaxel pharmacology, Protein Processing, Post-Translational, RNA, Small Interfering pharmacology, Receptor, ErbB-2 chemistry, Receptor, ErbB-2 physiology, Signal Transduction drug effects, Signal Transduction physiology, Trastuzumab, Wnt Proteins physiology, Antibodies, Monoclonal pharmacology, Antineoplastic Agents pharmacology, Breast Neoplasms pathology, Drug Resistance, Multiple physiology, Drug Resistance, Neoplasm physiology, Mucin-1 physiology, Neoplasm Proteins physiology
- Abstract
In the United States, 211,000 women are diagnosed each year with breast cancer. Of the 42,000 breast cancer patients who overexpress the HER2 growth factor receptor, <35% are responsive to treatment with the HER2-disabling antibody, called trastuzumab (Herceptin). Despite those statistics, women diagnosed with breast cancer are now tested to determine how much of this important growth factor receptor is present in their tumor because patients whose treatment includes trastuzumab are three-times more likely to survive for at least 5 years and are two-times more likely to survive without a cancer recurrence. Unfortunately, even among the group whose cancers originally respond to trastuzumab, 25% of the metastatic breast cancer patients acquire resistance to trastuzumab within the first year of treatment. Follow-on "salvage" therapies have prolonged life for this group but have not been curative. Thus, it is critically important to understand the mechanisms of trastuzumab resistance and develop therapies that reverse or prevent it. Here, we report that molecular analysis of a cancer cell line that was induced to acquire trastuzumab resistance showed a dramatic increase in the amount of the cleaved form of the MUC1 protein, called MUC1*. We recently reported that MUC1* functions as a growth factor receptor on cancer cells and on embryonic stem cells. Here, we show that treating trastuzumab-resistant cancer cells with a combination of MUC1* antagonists and trastuzumab, reverses the drug resistance. Further, HER2-positive cancer cells that are intrinsically resistant to trastuzumab became trastuzumab-sensitive when treated with MUC1* antagonists and trastuzumab. Additionally, we found that tumor cells that had acquired Herceptin resistance had also acquired resistance to standard chemotherapy agents like Taxol, Doxorubicin, and Cyclophosphamide. Acquired resistance to these standard chemotherapy drugs was also reversed by combined treatment with the original drug plus a MUC1* inhibitor.
- Published
- 2009
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15. Structural basis for the energetics of jacalin-sugar interactions: promiscuity versus specificity.
- Author
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Arockia Jeyaprakash A, Jayashree G, Mahanta SK, Swaminathan CP, Sekar K, Surolia A, and Vijayan M
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- Artocarpus chemistry, Calorimetry, Carbohydrate Metabolism, Crystallography, X-Ray, Models, Molecular, Molecular Sequence Data, Protein Subunits chemistry, Protein Subunits metabolism, Adjuvants, Immunologic chemistry, Adjuvants, Immunologic metabolism, Carbohydrates chemistry, Plant Lectins chemistry, Plant Lectins metabolism, Protein Conformation
- Abstract
Jacalin, a tetrameric lectin, is one of the two lectins present in jackfruit (Artocarpus integrifolia) seeds. Its crystal structure revealed, for the first time, the occurrence of the beta-prism I fold in lectins. The structure led to the elucidation of the crucial role of a new N terminus generated by post-translational proteolysis for the lectin's specificity for galactose. Subsequent X-ray studies on other carbohydrate complexes showed that the extended binding site of jacalin consisted of, in addition to the primary binding site, a hydrophobic secondary site A composed of aromatic residues and a secondary site B involved mainly in water-bridges. A recent investigation involving surface plasmon resonance and the X-ray analysis of a methyl-alpha-mannose complex, had led to a suggestion of promiscuity in the lectin's sugar specificity. To explore this suggestion further, detailed isothermal titration calorimetric studies on the interaction of galactose (Gal), mannose (Man), glucose (Glc), Me-alpha-Gal, Me-alpha-Man, Me-alpha-Glc and other mono- and oligosaccharides of biological relevance and crystallographic studies on the jacalin-Me-alpha-Glc complex and a new form of the jacalin-Me-alpha-Man complex, have been carried out. The binding affinity of Me-alpha-Man is 20 times weaker than that of Me-alpha-Gal. The corresponding number is 27, when the binding affinities of Gal and Me-alpha-Gal, and those of Man and Me-alpha-Man are compared. Glucose (Glc) shows no measurable binding, while the binding affinity of Me-alpha-Glc is slightly less than that of Me-alpha-Man. The available crystal structures of jacalin-sugar complexes provide a convincing explanation for the energetics of binding in terms of interactions at the primary binding site and secondary site A. The other sugars used in calorimetric studies show no detectable binding to jacalin. These results and other available evidence suggest that jacalin is specific to O-glycans and its affinity to N-glycans is extremely weak or non-existent and therefore of limited value in processes involving biological recognition.
- Published
- 2005
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16. Regulation of the TCRalpha repertoire by the survival window of CD4(+)CD8(+) thymocytes.
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Guo J, Hawwari A, Li H, Sun Z, Mahanta SK, Littman DR, Krangel MS, and He YW
- Subjects
- Animals, Apoptosis immunology, CD4-Positive T-Lymphocytes cytology, CD8-Positive T-Lymphocytes cytology, Cell Differentiation immunology, Cell Survival immunology, Chromatin immunology, DNA chemistry, DNA genetics, DNA isolation & purification, Flow Cytometry, Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor, Mice, Mice, Inbred C57BL, Mice, Transgenic, Nuclear Receptor Subfamily 1, Group F, Member 3, Polymerase Chain Reaction, Proto-Oncogene Proteins c-bcl-2 genetics, Proto-Oncogene Proteins c-bcl-2 immunology, Receptors, Antigen, T-Cell, alpha-beta genetics, Receptors, Cytoplasmic and Nuclear genetics, Specific Pathogen-Free Organisms, bcl-X Protein, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Receptors, Antigen, T-Cell, alpha-beta immunology, Receptors, Cytoplasmic and Nuclear immunology, Receptors, Retinoic Acid, Receptors, Thyroid Hormone
- Abstract
T cell receptor (TCR) alpha alleles undergo primary and secondary rearrangement in double-positive (DP) thymocytes. By analyzing TCRalpha rearrangement in orphan nuclear receptor RORgamma-deficient mice, in which the DP lifespan is shorter, and in Bcl-x(L)-transgenic mice, in which the DP lifespan is extended, we show that the progression of secondary V(alpha) to J(alpha) rearrangements is controlled by DP thymocyte survival. In addition, because Bcl-x(L) induces a bias towards 3' J(alpha) usage in peripheral T cells, we conclude that the programmed cell death of DP thymocytes is not simply a consequence of failed positive selection. Rather, it limits the progression of rearrangement along the J(alpha) locus and the opportunities for positive selection, thereby regulating the TCRalpha repertoire.
- Published
- 2002
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17. Specific complex formation between the type II bare lymphocyte syndrome-associated transactivators CIITA and RFX5.
- Author
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Scholl T, Mahanta SK, and Strominger JL
- Subjects
- B-Lymphocytes, Burkitt Lymphoma, Cloning, Molecular, DNA-Binding Proteins isolation & purification, Humans, Mutagenesis, Site-Directed, Polymerase Chain Reaction, Recombinant Fusion Proteins isolation & purification, Recombinant Fusion Proteins metabolism, Regulatory Factor X Transcription Factors, Trans-Activators isolation & purification, Transfection, Tumor Cells, Cultured, DNA-Binding Proteins metabolism, Genes, MHC Class II, Nuclear Proteins, Promoter Regions, Genetic, Trans-Activators metabolism, Transcription, Genetic, Transcriptional Activation
- Abstract
Two of the genes defective in the five complementation groups identified in the class II-negative bare lymphocyte syndrome or corresponding laboratory mutants have been cloned. One gene encodes a protein, RFX5, that is a member of the RFX family of DNA binding proteins. The other, CIITA, encodes a large protein with a defined acidic transcriptional activation domain; this protein does not interact with DNA. Expression plasmids encoding regions of RFX5 fused to the GAL4 DNA binding domain activated transcription from a reporter construct containing GAL4 sites in a cotransfection assay in the Raji human B cell line. However, these plasmids produced transcriptional activity in HeLa cells only in conjunction with interferon gamma stimulation, a condition in which expression of both CIITA and class II major histocompatibility complex surface proteins are induced. Furthermore, these plasmids were not active in RJ2.2.5, an in vitro mutagenized derivative of Raji in which both copies of CIITA are defective. Transcriptional activation by the RFX5 fusion protein could be restored in RJ2.2.5 by cotransfection with a CIITA expression plasmid. Finally, a direct interaction between RFX5 and CIITA was detected with the yeast two-hybrid and far-Western blot assays. Thus, RFX5 can activate transcription only in cooperation with CIITA. RFX5 and CIITA associate to form a complex capable of activating transcription from class II major histocompatibility complex promoters. In this complex, promoter specificity is determined by the DNA binding domain of RFX5 and the general transcription apparatus is recruited by the acidic activation domain of CIITA.
- Published
- 1997
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18. Transactivation by CIITA, the type II bare lymphocyte syndrome-associated factor, requires participation of multiple regions of the TATA box binding protein.
- Author
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Mahanta SK, Scholl T, Yang FC, and Strominger JL
- Subjects
- B-Lymphocytes, Binding Sites, Burkitt Lymphoma, Cloning, Molecular, DNA Primers, DNA-Binding Proteins chemistry, Glutathione Transferase biosynthesis, Humans, Models, Structural, Mutagenesis, Site-Directed, Point Mutation, Protein Structure, Secondary, Recombinant Fusion Proteins metabolism, Saccharomyces cerevisiae, TATA Box, TATA-Box Binding Protein, Transcription Factor TFIIB, Transcription Factors chemistry, Tumor Cells, Cultured, DNA-Binding Proteins metabolism, Genes, MHC Class II, Nuclear Proteins, Trans-Activators metabolism, Transcription Factors metabolism, Transcription, Genetic, Transcriptional Activation
- Abstract
CIITA is a positive regulator of class II major histocompatibility complex gene transcription that has been found to be defective in one of the five complementation groups of class II major histocompatibility complex-negative cell lines. Its N-terminal region is capable of activating transcription from a reporter gene when fused to a DNA binding domain. We have investigated the mechanism of transactivation mediated by the CIITA activation domain by studying its role in the process of transcription initiation and elongation. Specifically the altered specificity TBP (TATA box binding protein) assay has been used to analyze the response of the CIITA activation domain to mutations in TBP known to disrupt its interaction with its associated general factors. Transactivation by CIITA was extremely sensitive to a mutation in TBP that in yeast is known to abolish VP16-mediated transcription but leaves basal transcription unaffected. A TBP mutant defective in interaction with TBP-associated factor TAFII250 also failed to mediate transactivation through the CIITA activation domain. Certain interactions between TBP and general factors that are specifically required for acidic activation domains were also required for CIITA-mediated transactivation to reach its full potential. Finally, like VP16, CIITA was able to stimulate elongation of transcription. Overall the mechanism of transactivation by the human B-cell-specific CIITA is very similar to that mediated by the herpes virus transactivator VP16 in the ways that have been tested.
- Published
- 1997
- Full Text
- View/download PDF
19. Cooperativity between the J and S elements of class II major histocompatibility complex genes as enhancers in normal and class II-negative patient and mutant B cell lines.
- Author
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Sugawara M, Scholl T, Mahanta SK, Ponath PD, and Strominger JL
- Subjects
- Base Sequence, Burkitt Lymphoma pathology, Cell Line, Transformed, Genetic Complementation Test, HLA-D Antigens genetics, HLA-DP Antigens genetics, HLA-DP alpha-Chains, HLA-DQ Antigens genetics, HLA-DQ beta-Chains, HeLa Cells, Herpesvirus 4, Human, Humans, Interferon-beta biosynthesis, Interferon-beta genetics, Molecular Sequence Data, Promoter Regions, Genetic, Severe Combined Immunodeficiency genetics, Severe Combined Immunodeficiency pathology, Tumor Cells, Cultured, B-Lymphocytes immunology, Enhancer Elements, Genetic, Gene Expression Regulation, Genes, MHC Class II, HLA-D Antigens immunology, Severe Combined Immunodeficiency immunology
- Abstract
The class II major histocompatibility complex genes all contain in their proximal promoters three cis-elements called S, X, and Y that are conserved in both sequence and position, and a fourth element, J, conserved in sequence but not in position. J, X, and Y and, to some extent, S, have been shown to be functionally important in regulation of expression of these genes. In the present study, a protein factor that binds cooperatively to the S plus J elements of the promoter of the class II major histocompatibility complex gene DPA has been detected. Moreover, functional cooperativity between S and J in activation of the enhancerless -40 interferon-beta (-40 IFN-beta) promoter has been demonstrated. Finally, the latter assay appears to subdivide complementation group A of class II negative human B cell lines that includes both mutants generated in vitro and cells from patients with the bare lymphocyte syndrome (type II). In three of these cell lines, the enhancerless -40 IFN-beta promoter containing the S plus J elements was functionally active, while in the others it was inactive.
- Published
- 1995
- Full Text
- View/download PDF
20. Transmission of Sarcoptes scabiei from animal to man and its control.
- Author
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Mitra M, Mahanta SK, Sen S, Ghosh C, and Hati AK
- Subjects
- Adult, Animals, Cattle, Child, Disease Outbreaks, Dogs, Female, Goats, Hexachlorocyclohexane therapeutic use, Humans, India epidemiology, Insecticides therapeutic use, Male, Nitriles, Pyrethrins therapeutic use, Scabies drug therapy, Scabies epidemiology, Scabies veterinary, Sheep, Zoonoses, Scabies transmission
- Abstract
Outbreak of Sarcoptes scabiei in animals spilling over to man in close association was observed in two adjacent villages, Fewgram and Nurpur in the district of Birbhum, West Bengal, from mid-November to mid-December, 1991. Nineteen goats and one calf who did not receive any treatment died of sarcoptic manage. All infected animals got cured with external application of deltamethrin, a synthetic pyrethroid and triazapentadiene. Human cases were treated successfully with benzene hexachloride (2%).
- Published
- 1995
21. Crystal structure of peanut lectin, a protein with an unusual quaternary structure.
- Author
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Banerjee R, Mande SC, Ganesh V, Das K, Dhanaraj V, Mahanta SK, Suguna K, Surolia A, and Vijayan M
- Subjects
- Arachis chemistry, Crystallography, X-Ray, Models, Molecular, Peanut Agglutinin, Plant Lectins, Protein Conformation, Lectins ultrastructure
- Abstract
The x-ray crystal structure of the tetrameric T-antigen-binding lectin from peanut, M(r) 110,000, has been determined by using the multiple isomorphous replacement method and refined to an R value of 0.218 for 22,155 reflections within the 10- to 2.95-A resolution range. Each subunit has essentially the same characteristic tertiary fold that is found in other legume lectins. The structure, however, exhibits an unusual quaternary arrangement of subunits. Unlike other well-characterized tetrameric proteins with identical subunits, peanut lectin has neither 222 (D2) nor fourfold (C4) symmetry. A noncrystallographic twofold axis relates two halves of the molecule. The two monomers in each half are related by a local twofold axis. The mutual disposition of the axes is such that they do not lead to a closed point group. Furthermore, the structure of peanut lectin demonstrates that differences in subunit arrangement in legume lectins could be due to factors intrinsic to the protein molecule and, contrary to earlier suggestions, are not necessarily caused by interactions involving covalently linked sugar. The structure provides a useful framework for exploring the structural basis and the functional implications of the variability in the subunit arrangement in legume lectins despite all of them having nearly the same subunit structure, and also for investigating the general problem of "open" quaternary assembly in oligomeric proteins.
- Published
- 1994
- Full Text
- View/download PDF
22. Sarcoptes scabiei in animals spreading to man.
- Author
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Mitra M, Mahanta SK, Sen S, Ghosh C, and Hati AK
- Subjects
- Adult, Animals, Cattle, Cause of Death, Child, Disease Outbreaks prevention & control, Dogs, Female, Hexachlorobenzene therapeutic use, Humans, India epidemiology, Insecticides therapeutic use, Male, Pyrethrins therapeutic use, Scabies diagnosis, Scabies drug therapy, Scabies transmission, Sex Factors, Toluidines therapeutic use, Zoonoses, Animals, Domestic, Disease Outbreaks statistics & numerical data, Disease Outbreaks veterinary, Goats, Population Surveillance, Scabies epidemiology, Scabies veterinary, Sheep
- Abstract
An outbreak of Sarcoptes scabiei in animals was observed from mid-November 1991 to mid-December 1991 in two adjacent villages, Fewgram and Nurpur, in Birbhum District, West Bengal State, India, starting from goats to cattle, then to sheep and even to dogs. Nineteen goats and one cattle died of manage infection. The infection spread to man in the last week of December 1991, and affected forty-two human beings, tending and rearing animals. The animals treated with deltamenthrin (synthetic pyrethroid) and amitraz (triazapentadiene) were completely cured. In man, the disease seemed to be self-limited in some cases and 2% hexachlorobenzene was successfully used for treatment of the others. The outbreak was effectively controlled in March 1992.
- Published
- 1993
23. Primary structure of a Thomsen-Friedenreich-antigen-specific lectin, jacalin [Artocarpus integrifolia (jack fruit) agglutinin]. Evidence for the presence of an internal repeat.
- Author
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Mahanta SK, Sanker S, Rao NV, Swamy MJ, and Surolia A
- Subjects
- Amino Acid Sequence, Cyanogen Bromide metabolism, Hydroxylamine, Hydroxylamines, Interferon Inducers metabolism, Iodobenzoates, Lectins metabolism, Macromolecular Substances, Molecular Sequence Data, Peptides metabolism, Repetitive Sequences, Nucleic Acid, Serine Endopeptidases metabolism, Interferon Inducers chemistry, Lectins chemistry, Plant Lectins
- Abstract
Jacalin [Artocarpus integrifolia (jack fruit) agglutinin] is made up of two types of chains, heavy and light, with M(r) values of 16,200 +/- 1200 and 2090 +/- 300 respectively (on the basis of gel-permeation chromatography under denaturing conditions). Its complete amino acid sequence was determined by manual degradation using a 4-dimethylaminoazobenzene 4'-isothiocyanate double-coupling method. Peptide fragments for sequence analysis were obtained by chemical cleavages of the heavy chain with CNBr, hydroxylamine hydrochloride and iodosobenzoic acid and enzymic cleavage with Staphylococcus aureus proteinase. The peptides were purified by a combination gel-permeation and reverse-phase chromatography. The light chains, being only 20 residues long, could be sequenced without fragmentation. Amino acid analyses and carboxypeptidase-Y-digestion C-terminal analyses of the subunits provided supportive evidence for their sequence. Computer-assisted alignment of the jacalin heavy-chain sequence failed to show sequence similarity to that of any lectin for which the complete sequence is known. Analyses of the sequence showed the presence of an internal repeat spanning residues 7-64 and 76-130. The internal repeat was found to be statistically significant.
- Published
- 1992
- Full Text
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24. Preparation and X-ray characterization of four new crystal forms of jacalin, a lectin from Artocarpus integrifolia.
- Author
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Banerjee R, Dhanaraj V, Mahanta SK, Surolia A, and Vijayan M
- Subjects
- Plant Lectins, Plants, X-Ray Diffraction, Lectins chemistry
- Abstract
Four new crystal forms of the anti-T lectin from jackfruit (Artocarpus integrifolia) have been prepared and characterized. Three of them, two monoclinic (P21, a = 59.4 A, b = 83.3 A, c = 63.5 A, beta = 107.7 degrees; C2, a = 106.1 A, b = 53.9 A, c = 128.0 A, beta = 95.0 A) and one orthorhombic (C222(1), a = 98.1 A, b = 67.3 A, c = 95.1 A) were grown with 2-methylpentan-2,4-diol (MPD) as the precipitant while the fourth, an hexagonal form (P6(1)22, a = b = 129.6 A, c = 157.9 A), was obtained in the presence of methyl-alpha-D-galactopyranoside with polyethylene glycol 4000 as the precipitant. The reported relative molecular mass (Mr) of the lectin was found to be inconsistent with the solvent content of the crystals estimated using measured densities. The Mr was redetermined using size-exclusion chromatography in the presence of methyl-alpha-D-galactopyranoside and Ferguson-plot analysis of mobilities in polyacrylamide gel electrophoresis. The redetermined Mr (66,000) is consistent with the measured crystal densities. The orthorhombic and the hexagonal forms, which have one half molecule and one molecule, respectively, in the asymmetric unit, are suitable for high-resolution X-ray analysis.
- Published
- 1991
- Full Text
- View/download PDF
25. Further characterization of the saccharide specificity of peanut (Arachis hypogaea) agglutinin.
- Author
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Swamy MJ, Gupta D, Mahanta SK, and Surolia A
- Subjects
- Arachis, Binding Sites, Carbohydrate Sequence, Kinetics, Molecular Sequence Data, Monosaccharides chemistry, Monosaccharides metabolism, Oligosaccharides chemistry, Peanut Agglutinin, Plant Lectins, Lectins metabolism, Oligosaccharides metabolism
- Abstract
2-Dansylamino-2-deoxy-D-galactose (GalNDns) has been shown to bind to peanut (Arachis hypogaea) agglutinin (PNA) in a saccharide-specific manner. This binding was accompanied by a five-fold increase in the fluorescence of GalNDns. The interaction was characterized by an association constant of 0.15 mM at 15 degrees and delta H and delta S values of -57.04 kJ.mol-1 and -118.1J.mol-1.K-1, respectively. Binding of a variety of other mono-, di- and oligo-saccharides to PNA, studied by monitoring their ability to dissociate the PNA GalNDns complex, revealed that PNA interacts with several T-antigen-related structures, such as beta-D-Galp-(1----3)-D-GalNAc, beta-D-Galp-(1----3)-alpha-D-GalpNAcOMe, and beta-D-Galp-(1----3)-alpha-D-GalpNAc-(1----3)-Ser, as well as the asialo-GM1 tetrasaccharide, with comparable affinity, thus showing that this lectin does not discriminate between saccharides in which the penultimate sugar of the beta-D-Galp-(1----3)-D-GalNAc unit is the alpha or beta anomer, in contrast to jacalin (Artocarpus integrifolia agglutinin), another anti T-lectin which preferentially binds to beta-D-Galp-(1----3)-alpha-D-GalNAc and does not recognize beta-D-Galp-(1----3)-beta-D-GalNAc or the related asialo-GM1 oligosaccharide. These studies also indicated that, in the extended combining region of PNA which accommodates a disaccharide, the primary subsite (subsite A) is highly specific for D-galactose, whereas the secondary subsite (subsite B) is less specific and can accommodate various structures, such as D-galactose, 2-acetamido-2-deoxy-D-galactose, D-glucose, and 2-acetamido-2-deoxy-D-glucose.
- Published
- 1991
- Full Text
- View/download PDF
26. Topography of the combining region of a Thomsen-Friedenreich-antigen-specific lectin jacalin (Artocarpus integrifolia agglutinin). A thermodynamic and circular-dichroism spectroscopic study.
- Author
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Mahanta SK, Sastry MV, and Surolia A
- Subjects
- Animals, Carbohydrate Conformation, Carbohydrate Sequence, Erythrocytes drug effects, Hemagglutination Tests, Lectins pharmacology, Molecular Sequence Data, Rabbits, Spectrophotometry, Ultraviolet, Lectins metabolism, Plant Lectins
- Abstract
Thermodynamic analysis of carbohydrate binding by Artocarpus integrifolia (jackfruit) agglutinin (jacalin) shows that, among monosaccharides, Me alpha GalNAc (methyl-alpha-N-acetylgalactosamine) is the strongest binding ligand. Despite its strong affinity for Me alpha GalNAc and Me alpha Gal, the lectin binds very poorly when Gal and GalNAc are in alpha-linkage with other sugars such as in A- and B-blood-group trisaccharides, Gal alpha 1-3Gal and Gal alpha 1-4Gal. These binding properties are explained by considering the thermodynamic parameters in conjunction with the minimum energy conformations of these sugars. It binds to Gal beta 1-3GalNAc alpha Me with 2800-fold stronger affinity over Gal beta 1-3GalNAc beta Me. It does not bind to asialo-GM1 (monosialoganglioside) oligosaccharide. Moreover, it binds to Gal beta 1-3GalNAc alpha Ser, the authentic T (Thomsen-Friedenreich)-antigen, with about 2.5-fold greater affinity as compared with Gal beta 1-3GalNAc. Asialoglycophorin A was found to be about 169,333 times stronger an inhibitor than Gal beta 1-3GalNAc. The present study thus reveals the exquisite specificity of A. integrifolia lectin for the T-antigen. Appreciable binding of disaccharides Glc beta 1-3GalNAc and GlcNAc beta 1-3Gal and the very poor binding of beta-linked disaccharides, which instead of Gal and GalNAc contain other sugars at the reducing end, underscore the important contribution made by Gal and GalNAc at the reducing end for recognition by the lectin. The ligand-structure-dependent alterations of the c.d. spectrum in the tertiary structural region of the protein allows the placement of various sugar units in the combining region of the lectin. These studies suggest that the primary subsite (subsite A) can accommodate only Gal or GalNAc or alpha-linked Gal or GalNAc, whereas the secondary subsite (subsite B) can associate either with GalNAc beta Me or Gal beta Me. Considering these factors a likely arrangement for various disaccharides in the binding site of the lectin is proposed. Its exquisite specificity for the authentic T-antigen, Gal beta 1-3GalNAc alpha Ser, together with its virtual non-binding to A- and B-blood-group antigens, Gal beta 1-3GalNAc beta Me and asialo-GM1 should make A. integrifolia lectin a valuable probe for monitoring the expression of T-antigen on cell surfaces.
- Published
- 1990
- Full Text
- View/download PDF
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