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Considerable information exists on the physiological correlates of life history adaptation, while molecular data on this topic are rapidly accumulating. However, much less is known about the enzymological basis of life history adaptation in outbred populations. In the present study, we compared developmental profiles of fat body specific activity, kinetic constants of homogeneously purified and unpurified enzyme, and fat body enzyme concentration of the pentose-shunt enzyme, 6-phosphogluconate dehydrogenase (6PGDH, E.C.1.1.1.44) between the dispersing [long-winged, LW(f)] and flightless [short-winged, SW] genotypes of the cricket Gryllus firmus. Neither kcat nor the Michaelis constant for 6-phosphogluconate differed between 6PGDH from LW(f) versus SW morphs for either homogeneously purified or unpurified enzyme. Purified enzyme from the LW(f) morph exhibited reduced KM for NADP(+), but this was not observed for multiple KM(NADP+) estimates for unpurified enzyme. A polyclonal antibody was generated against 6PGDH which was used to develop a chemiluminescence assay to quantify 6PGDH concentration in fat body homogenates. Elevated enzyme concentration accounted for all of the elevated 6PGDH specific activity in the LW(f) morph during the juvenile and adult stages. Finally, activity of another pentose-shunt enzyme, glucose-6-phosphate dehydrogenase, strongly covaried with 6PGDH activity suggesting that variation in 6PGDH activity gives rise to variation in pentose shunt flux. This is one of the first life-history studies and one of the few studies of intraspecific enzyme adaptation to identify the relative importance of evolutionary change in enzyme concentration vs. kinetic constants to adaptive variation in enzyme activity in an outbred population., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Aim: To identify commonly occurring DNA copy number alterations in Korean cervical cancers., Methods: DNA copy number alteration was screened by whole-genome array comparative genomic hybridization (CGH) analysis. For the array CGH discovery, genomic DNA from five cervical cancers and 10 normal cervical tissues were examined. For the independent validation of the most significant chromosomal alteration (1p36.22, PGD gene), 40 formalin-fixed paraffin-embedded cervical tissue samples were collected; 10 of them were used for quantitative polymerase chain reaction and the other 30 samples were used for immunohistochemical analysis. Chromosomal segments differently distributed between cancers and normal controls were determined to be recurrently altered regions (RAR)., Results: A total of 13 RAR (11 RAR losses and two RAR gains) were defined in this study. Of the 13 cervical cancer-specific RAR, RAR gain in the 1p36.22 locus where the PGD gene is located was the most commonly detected in cancers (P = 0.004). In the quantitative polymerase chain reaction replication, copy number gain of the PGD gene was consistently identified in cervical cancers but not in the normal tissues (P = 0.02). In immunohistochemical analysis, PGD expression was significantly higher in cervical cancers than normal tissues (P = 0.02)., Conclusion: Our results will be helpful to understand cervical carcinogenesis, and the PGD gene can be a useful biomarker of cervical cancer., (© 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.)

In vivo pentose phosphate pathway (PPP) enzymes such as glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), and transaldolase (TAL) activities as well as ATP- and ADP-level variations of Amycolatopsis orientalis were investigated with respect to glucose concentration and incubation period. G6PDH, 6PGDH, and TAL activities of A. orientalis reached maximum levels at 48 hr for all glucose concentrations used, after which the levels began to decline. G6PDH, 6PGDH, and TAL activities showed positive correlation with the glucose concentration up to 15 g/L, while further increases had an opposite effect. Intracellular ATP level showed a positive correlation with glucose concentrations, while ADP level increased up to 15 g/L. ATP concentration of A. orientalis increased rapidly at 48 hr of incubation, as was the case also for G6PDH, 6PGDH, and TAL activities, although the incubation period corresponding to maximum values of ADP shifted to 60 hr. Production of the glycopeptide antibiotic vancomycin increased with the increases in glucose concentrations up to 15 g/L, by showing coherence in the rates of oxidative and nonoxidative parts of the PPP.

All New World Leishmania species can cause cutaneous lesions, while only Leishmania (Viannia) braziliensis has been associated with mucosal metastases. Multilocus enzyme electrophoresis (MLEE) is the optimal standard for species identification but is slow and costly. New methods for species identification are needed to ensure proper identification and therapy. The coding regions of four metabolic enzyme markers in the MLEE typing method: mannose phosphate isomerase (MPI), malate dehydrogenase (MDH), glucose-6-phosphate isomerase (GPI), and 6-phosphogluconate dehydrogenase (6PGD), were analysed from seven species of New World Leishmania isolated from patients with either cutaneous or mucosal lesions to identify specific genetic polymorphisms responsible for the phenotypic variations observed in the MLEE typing scheme. We identified species-specific polymorphisms and determined that a combination of sequencing of the mpi and 6pgd genes was sufficient to differentiate among seven closely related species of New World Leishmania and among isolates of L. braziliensis shown previously to have atypical MLEE patterns. When DNA isolated from 10 cutaneous lesion biopsies were evaluated, the sequence typing method was 100% concordant with the published MLEE/monoclonal antibody identification methods. The identification of species-specific polymorphisms can be used to design a DNA-based test with greater discriminatory power that requires shorter identification times. When the causative agent of the disease is L. braziliensis, this method ensures correct species identification, even when the agent is a genetic variant. Proper identification could facilitate adequate treatment, preventing the onset of the disfiguring mucosal form of the disease.

Forty-two dikaryotic and 42 monokaryotic isolates, and 34 pairings were examined by horizontal polyacrylamide gel electrophoresis (PAGE) for six enzymatic activities, viz. EST, 6PGD, IDH, MDH, SHDH and SOD. 44 bands were analysed. Numerical analysis of the isoenzymatic patterns was undertaken and compared with those from morphological characters. The analysis of six enzymatic systems showed the existence of four monomorphic systems (IDH, MDH, SHDH and SOD). The sterease system (EST) appears to be polymorphic in Polyporus ciliatus and in populations of P. tenuiculus from Argentina, being monomorphic in the remaining species studied. The 6PGD system is polymorphic in P. tucumanensis and monomorphic in the other species. Predominance of monomorphic enzymes and a clear distribution of the electromorphs among the species, indicates that isoenzymatic analysis is a good taxonomic tool within Polyporus. The low intraspecific variability allowed the use of interspecific differences to separate species. Numerical analysis showed a good correlation between morphological and molecular characters. In the isoenzymatic phenogram the similarity index is high only among very close species, showing a stressed separation of species.

In order to identify and characterise the organisms responsible for Cutaneous Leishmaniasis, parasites were isolated from active lesions, grown in-vitro cultures and identified by iso-enzyme characterisation. Thirteen isolates from different patients were typed as L. tropica. Seven of these isolates were from Afghan refugees encamped in the suburbs of Islamabad, 3 were from patients in Multan, 1 was from a patient from Azad Jammu and Kashmir and 1 was from Besham (Swat, NWFP). The study confirms the presence of anthroponotic Cutaneous Leishamaniasis caused by L. Tropica in Pakistan.

Channel catfish were collected on 11 different dates from October 1991 to July 1993 and acclimated in the laboratory to 7 degrees C, 15 degrees C, or 25 degrees C for 6 wk. Hepatosomatic index, mg protein mg-1 DNA, total liver DNA and protein, and the activities of liver glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, lactate dehydrogenase, and malate dehydrogenase were measured to examine seasonal variation in the acclimation response. Liver and muscle cytochrome oxidase and lactate dehydrogenase activities were measured to compare tissue-specific responses. Hepatosomatic indexes of fall and winter channel catfish were highest at 7 degrees C, with values at 15 degrees C higher than at 25 degrees C, while spring and summer fish had the highest values at 15 degrees C, with values at 7 degrees C higher than those at 25 degrees C. Acclimation patterns for total liver protein and DNA, mg protein mg-1 DNA, and glycogen were generally higher in cold temperatures but varied seasonally in an unpredictable manner. Glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and malate dehydrogenase demonstrated positive acclimation in the fall and winter; fish collected in the spring and summer showed little or inverse acclimation. Liver lactate dehydrogenase activity showed little or no positive compensation at any time of the year. Cytochrome oxidase activity showed positive acclimation in muscle but not liver. All liver enzymes, even those that showed marginal acclimation on a protein basis, showed positive acclimation when activity was expressed on a whole-liver basis.

The present investigation was designed to examine the effect of nickel deficiency on lipid metabolism in liver and serum lipoproteins of rats. Therefore, a study over two generations was conducted feeding a nickel-deficient diet containing 13 microg/kg nickel or a nickel-adequate diet supplemented with 1 mg/kg nickel. Male 7-wk-old pups from the second offspring were studied. Pups fed a diet poor in nickel tended to have lower weight gains (P < 0.15), nickel concentrations in liver (P < or = 0.1) and iron levels in serum (P < 0.1) than nickel-adequate rats. They were classified as nickel-deficient on the basis of significantly lower erythrocyte counts, hemoglobin concentrations, hematocrits and nickel concentrations in kidney compared with nickel-adequate rats. Nickel deficiency caused a significant triacylglycerol accumulation in liver, with greater concentrations of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids than nickel-adequate rats. Nickel deficiency had slight but significant effects on the fatty acid composition of liver total lipids and phosphatidylcholine and phosphatidylethanolamine. Moreover, nickel-deficient rats had significantly lower activities of the lipogenic enzymes glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, malic enzyme and fatty acid synthase than nickel-adequate rats. Nickel-depleted pups had significantly higher concentrations of triacylglycerols and phospholipids in serum VLDL, and cholesterol in serum LDL than nickel-adequate pups. Most of these alterations in lipid metabolism are similar to those obtained in several iron-deficiency studies. Because nickel deficiency also slightly compromised iron status, it is possible that at least some of the observed alterations are due to the moderate iron deficiency.

The main developmental stages in Helianthus annuus organogenesis have been studied in the sunflower hybrid "Giove". Shoot regeneration was obtained with high efficiency from mature seed cotyledons. Two-dimensional electrophoresis of protein extracts as well as the isozyme patterns of acid phosphatase, alcohol dehydrogenase, esterase, gluconate-6-phosphate dehydrogenase and phosphoglucomutase were compared during growth, callusing and regeneration. Two-dimensional protein patterns were similar, although polypeptides specific for each developmental phase could be identified. Different 2,4-dichlorophenoxyacetic acid concentrations or the sampling of specific regions of the seed did not result in significant differences in protein patterns. The activity of alcohol dehydrogenase and phosphoglucomutase appeared very low. For gluconate-6-phosphate dehydrogenase no difference, related either to the genotype or to different morphological stages, could be observed; the expression of acid phosphatase varied in a nonsystematic fashion. The isozyme pattern of esterase was related to the genotype as well as to the morphogenic phase.

SDS-PAGE and iso-enzyme analysis of 11 human isolates of Blastocystis hominis revealed at least two variants with different polypeptide patterns and two zymodemes, respectively. This is the first iso-enzyme and the second protein analysis to indicate strain differences in B. hominis.

The maximum activity and intracellular distribution of NADP(+)-linked malic enzyme in brain of Mammalia, Aves, Reptilia, Amphibia and Pisces are reported. Malic enzyme activity was present in all animals brains investigated. Most of the enzyme activity was located in the mitochondrial fraction. In brain of endothermic animals the activity of malic enzyme was several-fold higher than in ectothermic animals. Other NADPH-producing enzymes (i.e. NADP(+)-linked isocitrate dehydrogenase and hexosemonophosphate shunt dehydrogenase) activities were essentially similar in all animals brains tested. However, the total potential capability of NADPH production was lower in ectothermic animals (due mainly to lower malic enzyme activity). It is suggested that the presence of NADP(+)-linked malic enzyme in the brain may be related mainly to mitochondrial metabolism, especially to maintain the mitochondrial pool of NADP+ in reduced form.

Electrophoretic conditions including electrode and gel buffers, acrylamide concentration, use of stacking gels, voltage, current, and run time were investigated in order to produce isozyme bands of high resolution which would facilitate densitometric quantification of enzyme activity following polyacrylamide gel electrophoresis (PAGE). Electrode buffers which provided optimal conditions for gels stained for the isozymes of malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (6-PGD), phosphoglucose isomerase (PGI), and shikimate dehydrogenase (SkDH) were 0.02 M Tris-glycine, pH 8.5, 0.1 M sodium borate, pH 6.0, 0.1 M sodium borate, pH 8.7, and 0.07 M sodium borate, pH 7.0, respectively. A 0.5 M Tris-HCl, pH 7.5, gel buffer was optimal for gels stained for the isozymes of 6-PGD, PGI and SkDH. A 0.5 M Tris-HCl, pH 8.5, gel buffer was best for gels stained for MDH. Stacking gels were found to be detrimental to enzyme activity and showed no improvement in resolution for any of the enzymes. Acrylamide concentration for gels stained for MDH were 8.7%, gels stained for 6-PGD and PGI were 7.5%, while gels stained for SkDH had an acrylamide concentration of 5.0%. Higher concentrations above these levels caused a reduction and in some cases loss of band activity, while below this concentration there was a decrease in band resolution.(ABSTRACT TRUNCATED AT 250 WORDS)

A 16-wk experiment was conducted to compare the utilization of four carbohydrates by rainbow trout (Oncorhynchus mykiss) fed either continuously or four meals daily. The carbohydrates were glucose, maltose, dextrin and raw cornstarch, and were included at 32 g/100 g diet. Average initial body weight of the fish was 5.5 g, and fish were fed at a restricted rate of 2.0% body wt/d. Significant (P < 0.05) interactions between feeding strategy and carbohydrate were observed only for specific growth rate, final body weight, feed efficiency, and protein and energy retained. These measurements as well as whole-body moisture and lipid concentrations were also significantly higher in the continuously fed trout than in the meal-fed trout. Liver weight:body weight ratio, liver glycogen concentration, and liver lipogenic enzyme activities generally were higher in the continuously fed trout than in the meal-fed trout. Trout fed the glucose diet and those fed the maltose diet had higher specific growth rates, final body weights, feed efficiencies, energy retained, and whole-body and visceral moisture and lipid concentrations than those fed the starch diet. Trout continuously fed the glucose and maltose diets also had higher glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities than those continuously fed the starch diet. The higher protein and energy retained and the higher lipogenic enzyme activities in the continuously fed fish compared with the meal-fed fish showed that in trout growing slowly due to a restricted ration, continuous feeding improved the carbohydrate utilization and increased lipid storage by enhancing lipogenesis.

As part of our inquiries into the regulation of the hexose monophosphate shunt in the early development of sea urchin eggs and embryos, we have developed a novel method to assess the in vivo activity of the enzyme 6-phosphogluconate dehydrogenase (6PGDH) before and after fertilization. Our measurements show that the intracellular level of 6-phosphogluconate (6PG) in eggs decreases 60% after fertilization, which is consistent with the increase in the activity of 6PGDH previously reported using irreversibly permeabilized cell assays (Swezey and Epel, Proc. Natl. Acad. Sci USA 85, 812-816, 1988). The in vivo turnover of the 6PG pool was assessed using a new radioisotopic technique. 1-14C-labeled 6PG was chemically modified such that it was not metabolized by cellular 6PGDH and could be rapidly converted back to 6PG by photolysis. This "caged" 6PG was introduced into unfertilized sea urchin eggs using a transient permeabilization procedure, and then the oxidation of [1-14C]6PG in vivo upon irradiation was followed. Oxidation of 6PG was complete within 7-11 s of irradiation, indicating an extremely rapid turnover of this pool in sea urchin eggs. Based on the 6PG pool sizes and the kinetic properties of 6PGDH, determined here, along with the activity levels seen in permeabilized cells, the half-time for the label in the 6PG pool in sea urchin eggs is calculated to be 26 s. This is inconsistent with the in vivo turnover rates seen in these studies, indicating that the permeabilized cell assays overestimate the degree of inhibition of 6PGDH before fertilization. These results suggest that caution should be exercised in extrapolating data obtained from permeabilized cells to the situation in vivo.

The activity of 6-phosphogluconate dehydrogenase (6-PGDH) decreases in aged human erythrocyte populations. The aged enzyme has 11 lysine residues less than the young enzyme, when they are measured with 2,4,6-trinitro-benzenesulfonic acid (TNBS). Treatment of young enzyme with ascorbate for 15 min produces the loss of 8 lysine residues and the diminution of enzymatic activity. These results suggest that there is a modification of lysine residue in human erythrocytes during senescence, probably caused by oxidation. This modification of lysine residue could imply the loss of enzymatic activity. This result is similar to that found in rat liver 6-PGDH during aging, described previously (Gordillo et al., J. Biol. Chem. 264 (1989) 17014-17019).

The efficacy of the addition of prednisolone to tamoxifen as adjuvants to mastectomy in patients with primary breast cancer who were at a high risk of recurrence was investigated in a randomized trial. Primary carcinomas were collected from a series of 169 patients with loco-regional disease, undergoing mastectomy. The activities of alpha-glycerolphosphate dehydrogenase and 6-phosphogluconate dehydrogenase in the carcinomas were estimated biochemically and the ratio of the two enzymes was used to as the parameter to determine the risk of recurrence. 116 patients with a high risk of recurrence within five years of mastectomy were then randomized to either tamoxifen (2x20 mg/day) or tamoxifen+prednisolone (3x2.5 mg/per day) until recurrence. The patients are currently followed quarterly. The data were analysed at a median follow-up of 26 months (range 7-62 months). The probabilities of both disease-free and overall survival were not significantly different in either arm of the trial, indicating that there is no advantage in combining prednisolone with the antioestrogen. Recently, similar findings in terms of response have been reported for patients with metastatic disease treated with the same combination, raising doubts over the role of prednisolone in the management of patients with endocrine treatments.

Human urethral glands were reacted histochemically and immunohistochemically to identify glycoproteins, some androgen metabolic enzymes, and VIP-like immunoreactivity. Neutral/acid mucosubstances were detected mainly in the apical cytoplasm of the principal cells. 3 beta-, 17 beta-, and 3 alpha-hydroxysteroid dehydrogenase, G6PD, and 6PGD reactivity were intense in all the glandular epithelium. Small amounts of VIP-positive fibers were noted around the secretory elements.

Polymorphism of PGD was investigated in bloodstains, organ tissues, dental pulps, hair roots and semen by isoelectric focusing. This technique provided much higher resolution of PGD isoenzymes than starch gel electrophoresis. Phenotyping was possible from bloodstains for 5 weeks, from organ tissues (except pancreas) for 1-3 weeks, from dental pulps for 2 weeks and from hair roots for 2 weeks when they were stored at room temperature. The method is simple, rapid, reliable and therefore useful in medicolegal individualization of bloodstains, organ tissues, teeth and hairs.

Trials were conducted to determine the accuracy of separating the sympatric sand fly species Phlebotomus papatasi (Scopoli) and P. langeroni Nitzulescu by means of cellulose acetate enzyme electrophoresis. Malic enzyme, phosphoglucomutase, 6-phosphogluconate dehydrogenase, and fumarate hydratase were each evaluated in laboratory-reared and field-collected populations of the two species. Each of the four enzyme-based identifications was highly sensitive (greater than 97%) and specific (greater than 93%). Identifications based upon fumarate hydratase were in perfect agreement with morphological identifications, and evidence was obtained which indicates that this enzyme may be the most stable of the four enzymes tested. The application of enzyme-based vector identification is discussed in relation to classical and novel survey procedures for Leishmania promastigote detection in sand flies.

Red-cell enzymes and reduced glutathione (GSH) were assayed on cord blood in 307 Indian neonates. On follow-up, 20 of them developed pathologic jaundice. Of these, six had red-cell enzyme/GSH deficiency, seven had associated non-enzymatic causes of jaundice, and in the remaining seven the cause could not be diagnosed. In 41 other neonates, there was enzyme/GSH deficiency without pathologic jaundice. The degree of enzyme deficiency had no relation with jaundice. Red-cell enzyme/GSH deficiency state in neonates was associated with pathologic jaundice more frequently (six of 47; 12.8%) than in the absence of such deficiency (14 of 260; 5.4%). None of the jaundiced patients had very high levels of bilirubin nor needed exchange blood transfusion. There was no reduction in haemoglobin level in the enzyme/GSH deficient group with jaundice in comparison with non-deficient jaundiced neonates or normal subjects. The incidence of red-cell enzyme/GSH deficiency appears to be high in Indian neonates; however, the majority of them do not precipitate pathologic jaundice.

Previous studies by our laboratory have shown that lead nitrate when injected intravenously as a single dose to rats, induces a hyperplastic response in the liver. Liver hyperplasia was accompanied by an increase in cholesterol synthesis, an accumulation of cholesterol esters and by a stimulation of hexose-monophosphate (HMP) shunt enzyme activities. In the present report, hepatic DNA, mitotic index, cholesterol metabolism, as well as glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activities, were investigated during liver hyperplasia induced by lead in fasted rats. Fasting was chosen as an experimental model characterized by a very strong depression of those metabolic pathways (cholesterol synthesis and HMP shunt) that we have found related to liver hyperplasia. The mitogenic response, even if at minor extent, also occurs in liver of fasted rats. A stimulation of cholesterol synthesis and HMP shunt enzyme activities, was also observed in lead-treated fasted rats, adding further support to the fact that an endogenous source of newly synthesized cholesterol together with a suitable increase of HMP shunt enzyme activities is needed during hepatic cell proliferation.

Forty clones of Leishmania major were derived by direct plating from lesions and from cultures of recent isolates, followed by plating as well as by additional limit dilution in some. The parental strains originated from and represented three geographical areas in each of which a distinct electrophoretic type of the enzyme 6-phosphogluconate dehydrogenase (6PGD) is found. Each clone was characterized in terms of its virulence in Sabra mice, morphology, serotype, enzyme electrophoretic profile based on 11 enzymes, and kinetoplast DNA endonuclease restriction pattern. All the clones showed a similar virulence in the mice and similar polymorphism in fresh drops of living cultures and in Giemsa-stained preparations. Ten clones from the Jordan Valley were all serotype A1, 15 clones from the Arava were all A1Bz--confirming the mixed serological nature of parasites from this region, 11 of the 20 clones from the western Negev-eastern Sinai included a new A subserotype, and 9 were A1. Generally, the geographical separation of the 6PGD variants was upheld. Two of the Jordan Valley clones were similar to those of the western Negev. On two occasions, different enzyme types were isolated from the same individual, in one case from the same lesion. All clones from the western Negev were alike and similar to the type previously found in that region. The situation in the Arava was more complicated, since clones representative of all three regional types were found. In cases where the first two types were found, the clones and their parental strains were similar. However, one parental culture yielded three clones that resembled the reference strain for the Jordan Valley and two which resembled that of the western Negev. In one of these cases, two dissimilar clones originated from the same lesion. One aberrant clone from the western Negev was variant for nucleoside hydrolase. The kinetoplast DNA of each clone was distinct but relatively complicated, which made differentiation of these regional types difficult. However, clones from the same area displayed more similarity to each other than to those of other regions, implying a closer genetic relationship.

Possibility of combined determination of phenotypes of three enzyme system (glyoxylase-1, phosphoglucomutase and 6-phosphogluconate dehydrogenase) in the apparatus with two vertical blocks of polyacrilamide gel (PAAG) was shown. The method is based on the principle of combination of differently composed blocks of PAAG and single universal electrode buffer. High productivity and economy of the method equally with good quality of resulting phoregrams make this method useful for medicolegal practical work.

The influences of phenobarbital (PB) on enzymes of the carbohydrate metabolism in rat liver are examined during pre- and postnatal development. The following results are obtained: (1) PB generally increases G-6-Pase before and after birth. (2) Both the active and the inactive forms of phosphorylase are increased significantly during the prenatal periods. During the postnatal periods, mainly the active form of phosphorylase is influenced by PB. (3) Total glycogen synthetase is increased by PB during prenatal development but decreased during postnatal development. (4) The activity of alpha-glucosidase is increased during the prenatal period. (5) The activity of F-6-PK and 6-PGDH are decreased during the prenatal periods and G-6-PDH activity is decreased during both pre- and postnatal periods.

An improved method has been developed for the assay of hexokinase (EC 2.7.1.1) levels in human tissue homogenates. The enzyme is quantitated by the spectrophotometric measurement, at 340 nm, of NADPH formed according to the reaction scheme: [formula: see text] In tissue homogenates a number of enzymes are present which can interfere with the assay by reacting with substrates or products of the assay reactions. In the described procedure hexokinase is assayed directly in homogenates under conditions in which the effect of possible contaminating enzymes (glucose dehydrogenase, EC 1.1.1.47; glucose 6-phosphatase, EC 3.1.3.9; glucose phosphate isomerase, EC 5.3.1.9; 6-phosphogluconate dehydrogenase EC 1.1.1.44; and NADP-reducing enzymes) are eliminated. Precision studies on the assay gave within-day reproducibility of 4.3% (CV) on a tissue having a mean activity of 1.68 U/g of tissue, and day-to-day variability of 15% (CV) for a tissue averaging 1.83 U/g of tissue.

Anthropological studies were done on 1276 Libyans from the Mediterranean cities of Tripoli and Benghazi, and from Sabha southward in The Sahara. The incidences of hemoglobin (Hb)-S and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency were low in the coastal areas and significantly high in Sabha. Hb-C occurred sporadically in Tripoli and Sabha, and was absent from Benghazi in the east. One case of Hb-J Benghazi was noted. There were no sigificant differences in the ABO blood group and Rh0 (D) type distributions in the three localities. G-6-PD gene GdAfrequency was significantly high in Sabha. The lowest value of 6-phosphogluconate dehydrogenase (6-PGD) gene PGDA frequency and highest value of the gene PGDC were in Sabha. Adenylate kinase (AK) gene AK2 was only detectable in Tripoli. Acid phosphatase (AP) gene Pa frequency in Sabha was more than twice that in Tripoli and Benghazi, while pc was distinctly lower in Sabha than in the northern cities. Haptoglobin gene Hp1 frequency was almost identical in all areas. Anthropometric measurements revealed overall homogeneity of the three samples, closer similarity in the coastal region to adjacent North African populations, and Negroid influence in the Sahara Libyans. Anthropometry substantiated findings from blood markers.

Isolates of Plasmodium falciparum collected from the east and west coasts of tropical Africa and also from several inland regions have been examined for electrophoretic forms of the enzymes GPI, LDH and 6PGD. Variation within and between isolates was found in the parasite forms of all three enzymes. While not disproving the existence of genetic divisions between P. falciparum populations in Africa the distribution of this variation provides no evidence for such a hypothesis.

A 6.0-kilobase EcoRI fragment of the Pseudomonas aeruginosa PAO chromosome containing a cluster of genes specifying carbohydrate catabolism was cloned into the multicopy plasmid pRO1769. The vector contains a unique EcoRI site for cloning within a streptomycin resistance determinant and a selectable gene encoding gentamicin resistance. Mutants of P. aeruginosa PAO transformed with the chimeric plasmid pRO1816 regained the ability to grow on glucose, and the following deficiencies in enzyme or transport activities corresponding to the specific mutations were complemented: glcT1, glucose transport and periplasmic glucose-binding protein; glcK1, glucokinase; and edd-1, 6-phosphogluconate dehydratase. Two other carbohydrate catabolic markers that are cotransducible with glcT1 and edd-1 were not complemented by plasmid pRO1816: zwf-1, glucose-6-phosphate dehydrogenase; and eda-9001, 2-keto-3-deoxy-6-phosphogluconate aldolase. However, all five of these normally inducible activities were expressed at markedly elevated basal levels when transformed cells of prototrophic strain PAO1 were grown without carbohydrate inducer. Vector plasmid pRO1769 had no effect on the expression of these activities in transformed mutant or wild-type cells. Thus, the chromosomal insert in pRO1816 contains the edd and glcK structural genes, at least one gene (glcT) that is essential for expression of the glucose active transport system, and other loci that regulate the expression of the five clustered carbohydrate catabolic genes. The insert in pRO1816 also complemented the edd-1 mutation in a glucose-negative Pseudomonas putida mutant but not the eda-1 defect in another mutant. Moreover, pRO1816 caused the expression of high specific activities of glucokinase, an enzyme that is naturally lacking in these strains of Pseudomonas putida.

Two lines of Plasmodium chabaudi differing in three characters have been crossed, using a technique previously described for P. yoelii. One line, termed 47AS, was characterized by an electrophoretic form of 6-hosphogluconate dehydrogenase, denoted 6PGD-2, a form of lactate dehydrogenase, denoted LDH-3, and was pyrimethanime-resistant. The second line, termed 10AJ, possessed enzyme forms of 6PGD-3 and LDH-2 and was pyrimethamine-sensitive. The cross was made by permitting mosquitoes to feed on a mixture of the two lines and infecting rodents with the resulting sporozoites. The products of the cross were cloned by dilution and examined for enzyme-type and drug-response. Results showed that recombination had occurred between each of the three characters. Clones characterized by 6PGD-2/LDH-2 and 6PGD-3/LDH-3 demonstrated recombination between the enzyme markers. The drug-resistance character segregated independently of either enzyme marker.

There is insufficient evidence of direct oxidation of glucose through the pentose phosphate cycle in mammalian spermatozoa. We separated the key enzymes (G6P-DH, 6PG-DH) in the pentose pathway using 2',5'ADP-Sepharose 4B. The purpose of this study is to establish the intracellular location of these two enzymes in boar spermatozoa and testis by histochemical techniques. Histochemical localization of the two pentose phosphate pathway dehydrogenases was achieved by the use of the tetrazolium salt nitro blue tetrazolium (Nitro BT). Both G6P-DH and 6PG-DH was present in the mid pieces of boar spermatozoa and in the Leydig cells and seminiferous tubules of testis. The present findings indicate that the pentose pathway could be involved in the energy production of spermatozoa and that these enzymes may be important in supplying NADPH for steroid synthesis in the testis.

As yet, there is no report available on the stability studies of 6-phosphogluconate dehydrogenase enzyme in India. 469 bloodstains prepared in the laboratory using a variety of substrates commonly encountered in case examination have been analysed by starch gel electrophoresis. The utility of this parameter under various climatic conditions prevalent in India has also been evaluated. Except in the cases of relatively fresh samples of blood, the PGD isoenzyme system seems not to be very suitable in Indian conditions.

Four different unusual 6-phosphogluconate dehydrogenase (6-PGD) electrophoretic patterns found among the Italian (Rome), Bamileke (Cameroon), and North Bateke and Babenga Pygmy (Congo) populations are described.

The activities of three enzymes of the hexose monophosphate pathway (HMP) were measured in frozen samples of rat cerebral cortex and ethylnitrosourea-induced tumors of the rat nervous system. Results show that in most tumors, adequate amounts of glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), and transketolase (TK) were present so as not to be rate-limiting for utilization of the HMP. When enzyme activites were expressed on the basis of fresh weight, TK was increased in most tumors as compared with cerebral cortex; G6PDH and 6PGDH were more variable, showing either higher or lower activities in tumors as compared to control. Tumors in general had a lower protein content than cerebral cortex. When activities were expressed in terms of this protein content, mean values for the dehydrogenases in all groups of tumors were higher than the average value in cortex, indicating that G6PDH and 6PGDH were spared in tumors relative to other proteins. TK activities in tumors, expressed in terms of cytosol protein were lower than or in the same range as cortex. Increased activities of HMP enzymes in some tumors indicated that the potential activity of the HMP in some (but not all) tumors of the nervous system is greater than that of cerebral cortex.

1. 6-phosphogluconate dehydrogenase from sheep liver has been purified 350-fold by affinity chromatography with a final specific activity of 18 micronmol of NADP+/reduced min per mg of protein and an overall yield of greater than 40%. 2. A systematic investigation of potential ligands has been carried out: these included 6-phosphogluconate and NADP+, pyridoxal phosphate and several immobilized nucleotides. The results indicate that NADP+ is the most suitable ligand for the purification of 6-phosphogluconate dehydrogenase. 3. The effects of pH and alternative eluents have been examined in relation to the parameters known to affect the desorption phase of affinity chromatography; careful manipulation of the elution conditions permitted the separation of glucose 6-phosphate dehydrogenase, glutathione reductase and 6-phosphogluconate dehydrogenase from sheep liver on NADP+-Sepharose 4B. 4. A large-scale purification scheme for 6-phosphogluconate dehydrogenase is presented that uses the competitive inhibitors inorganic pyrophosphate and citrate as specific eluents.

6-Phosphogluconate dehydrogenase (6-phospho-D-gluconate: NADP+ 2-oxidoreductase(decarboxylating), EC 1.1.1.44) from Candida utilis is inhibited by reaction with pyridoxal 5'-phosphate. The aldehydic group of this compound forms a Schiff base with the epsilon-amino group of a lysine residue: reduction of this enamine with tritiated borohydride can label this amino acid. Two tryptic peptides, TS2 and TS3, have been isolated from the labelled protein and found to have the following amino acid sequences: TS2: Ile-Leu-Asx-Glx-Ala-Gly-Gly-Lys(P-Pxy)-Gly-Glx-Thr-Lys TS3: Thr-Val-Ser-Lys(P-Pxy)-Val-Asp-His-Phe-Ile-(Glx,Asx,Glx)-Ala-Lys where Lys(P-Pxy) indicates the modified lysine residue. The similarities between the amino acid sequences around the pyridoxal phosphate binding lysines of 38 peptides, obtained from enzymes which have pyridoxal phosphate as cofactor or inhibitor, are discussed and a prediction is made on the presence of reverse turns in these peptides.

A survey of protein variability has been made in wild populations of Silene maritima, a perennial outcrossing coastal plant. In the most extensively studied populations, at Beesands, six out of 21 loci were polymorphic, and the average heterozygosity was 0.153. Four polymorphic loci were studied on an extensive shingle beach at Dungeness. Three loci showed no frequency cline with distance from the sea; a fourth locus, that for adenylate kinase, showed a barely significant cline, which was not confirmed by a repeat study in the same place a year later. Five polymorphic loci were studied at Beesands along a strip of shingle beach and up a contiguous cliff. No frequency difference between the two habitats was observed. There are significant differences in allelic frequencies between localities. It is concluded that the data fail to show an association between habitat and gene frequency, although they were collected in such a way as to be capable of demonstrating such an association if it existed.

Hybridomas were made between NS1/1-Ag4-1 mouse myeloma cells and spleen and lymph node cells from a sheep immunized with sheep red cells (RBC). The hybrid colonies grew well in culture but there was a substantial loss of sheep chromosomes. No hemolytic or agglutinating antibodies were detected in the culture supernatants after the 17th day following fusion, but immunofluorescence tests indicated that a few of the cells may have been expressing sheep IgG. Cytogenetic comparison of cells grown with and without HAT medium provided evidence that the enzyme HGPRT is located on the X chromosome of sheep as it is in man and mouse. Hybridoma isozyme patterns of esterase, G6PD, 6PGD, NP, LDH and SOD tested between the 63rd and 71st day of culture were like those of NS1; NP and LDH also showed zones that probably came from the sheep component.

The activities of selected glycolytic enzymes in breast tumor tissues were examined based on earlier studies showing a relationship between therapy and/or prognosis of breast cancer and tissue enzyme. In the present study, five glycolytic enzymatic activities (pyruvate kinase [PK], glucose-6-phosphate dehydrogenase [G6PD], phosphohexose-isomerase [PHI], lactate dehydrogenase [LDH], and 6-phospho-glucocate dehydrogenase [6PGD]) were measured in the cytosol (105,000 g) of 57 breast carcinomas and 22 benign breast lesions. Nucleic acids and DNA were also determined. The results were related to the wet weight of the tissue, to total and tissue cytosol proteins, and to DNA. The various means of expressing the results were compared. The correlations were satisfactory except for PHI and LDH. In these cases, this might have been due to blood contamination. The enzyme activities content was lower in the benign breast lesions than in the breast carcinomas irrespective of the way the results were expressed.