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The purpose of the paper was to explore the effect of adding different levels of soybean active peptides to the diet on the growth performance, carcass traits, serum biochemical indexes and intestinal microorganisms of finishing pigs. A total of 120 finishing pigs with a weight of (72.40±1.10) kg were randomly divided into four groups, with three replicates in each group and 10 pigs in each replicate. The finishing pigs in the control group were fed a basic diet, and group A, group B and group C added 0.2%, 0.4% and 0.6% soybean active peptides in the basic diet, respectively. The experiment lasted for 42 days. The results showed that the average daily gain of the finishing pigs was significantly increased by adding soybean active peptide (P<0.05). Compared with the control group, the feed-to-weight ratio of the group B was significantly reduced (P<0.05), and the feed-to-weight ratio and average back fat thickness of the group C were significantly reduced ( P<0.05). Adding soybean active peptide could improve the meat color and significantly reduce the dripping loss of the finishing pigs in the group B and group C (P<0.05). Compared with the control group, the content of serum MDA in the experimental groups decreased significantly (P<0.05), the content of serum BUN in the group B and group C decreased significantly (P<0.05), the content of IgM and T-AOC increased significantly (P<0.05). The activity of serum AST and GSH-Px in the group C decreased significantly, and the content of IgG increased significantly (P<0.05). The flora with a relative abundance of more than 1% at the phylum level in each experimental group included Firmicutes, Proteobacterium and Bacteroides, and the relative abundance of Proteobacterium in the group C was significantly lower than that in the control group (P<0.05). The flora with a relative abundance over 1% at the genus level included Actinomycetes, Coprococcus, Clostridium and Enterobacter, and there was no significant difference in the relative abundance of each genus compared with the control group (P>0.05). The study indicates that adding 0.4%~0.6% soybean active peptide to the diet can improve the growth performance, modify carcass traits, adjust serum biochemical indexes, and affect the intestinal microbial composition of finishing pigs. [ABSTRACT FROM AUTHOR]

Proteins are the carriers of biological structure and function, which are involved in almost all the physiological processes in organisms. The qualitative and quantitative analysis of proteins can not only help us understand the mechanisms of life activities, but also screen for the proteins with abnormal expression compared to healthy controls as biomarkers of diseases as well as environmental exposure to harmful substances, thus facilitating to unravel the mechanisms of disease generation and development. Tandem mass spectrometry (MS/MS) is currently the main tool for high-throughput proteomics analysis. It can characterize the proteins by determining the molecular mass of digestion products, locating modification sites, and obtaining sequence information. However, acidic amino acid residues often have a significant impact on the cleavage process of peptides, limiting the performance of MS/MS. For example, for the phosphopeptides containing abundance of negatively charged carboxyl and phosphoryl groups, their ionization is not efficient in the positive mode, and neutral loss is easy to occur during the cleavage process, resulting in a low coverage of product ions in the MS/MS spectra. In this paper, the carboxyl groups from the R group of aspartic acid and glutamic acid as well as the C-terminus of peptide were neutralized using dimethylamine derivatization under mild condition. Accordingly, the fragmentation features of peptides with altered charge properties were studied in collision-induced dissociation (CID) mode. Further, the peptides were labeled using light and heavy isotopic dimethylamine, respectively, thus enabling to verify the features based on the same ion with different labels. The results showed that the precursor ion signal from the derivatized peptide was significantly enhanced compared to that of the native peptide. And, the derived peptides could yield a variety of a, b, y, and z ions, and some reported ions in MS/MS analysis, such as the ion at m/z 129.10/135.14 produced by the peptides with glutamic acid or lysine residue at C-terminus, which facilitating to determine the C-terminal amino acid of protein. While, the peptides proned to lose the derivative groups located at the C-terminus, yielding a series of ions at m/z ［yn-45.06］ or ［yn-73.05] In addition, the neutralization of carboxyl groups could suppress the loss of phosphoryl groups in phosphopeptides to a certain extent, thus improving the resolution efficiency of the MS/MS spectra. Overall, the derivatization method based on carboxyamidation can provide abundant information for the sequence determination and quantitative analysis of peptides due to the altered fragmentation features in CID mode. [ABSTRACT FROM AUTHOR]

Given that wet experimental methods were no longer adequate for the rapid identification of bitter peptides, this paper presented Bitter-Fus, a novel predictive deep learning method incorporating traditional manual features and pre-trained deep features. Firstly, the method automatically extracted deep learning features from peptide sequences using a pre-trained protein sequence language model, then fed the deep learning features into a long short-term memory (LSTM) network for dimensionality reduction to retain the most relevant features. Finally, the reduced-dimensional deep features were fused with the manual features composed of traditional amino acids composition (AAC) method and passed into the feedforward neural network to construct a prediction model. The validation experimental results showed that the prediction method Bitter-Fus obtained an accuracy precision value of 0. 902 and a Mathews correlation coefficient value of 0. 805 in a 10-fold cross-validation, and an accuracy precision value of 0. 930 and a Mathews correlation coefficient value of 0. 862 in the independent dataset test, which significantly outperformed the current state-of-the-art bitter peptide prediction methods BERT4Bitter and iBitter-SCM. [ABSTRACT FROM AUTHOR]

AMPs is widely found in animals and plants. AMPs is a kind of small peptide composed of about 12~50 amino acids produced by process of transcription and translation of special genes in body cells, which is an important part of the body's innate immunity and constitutes the first line of defense of the body against pathogenic microorganisms. AMPs has a wide range of distribution, broad-spectrum antibacterial activity, not easy to produce drug resistance, high thermal stability, antiviral and other effects. AMPs as a feed additives is widely used in poultry disease control and prevention, immunity enhancement, improve intestinal flora, poultry growth performance and many aspect. The paper elaborates the types of AMPs, anti-bacterial effects, anti-viral effects, disease prevention and control, improvement of intestinal flora and improvement of poultry growth performance, to provide reference for the later research and application of AMPs. [ABSTRACT FROM AUTHOR]

This paper first preseats a brief introduction to molecular biology, focusing on nucleotides and amino acids, the basic units of nucleic acid and protein sequence. With well-designed figures and tables, the name, classification, and property of four nucleotides and 20 amino acids are displayed. General concepts related to sequence alignment are described in the second section, including similarity and homology, global and local alignment, the dot plot method, dynamic and heuristic programming, scoring matrix and gap penalty, and alignment tools and platforms. The third part introduces the scoring matrices, which play a critical role in sequence alignment. Characteristics of DNAfull for DNA sequence, as well as BLOSUM62 and PAM250 for protein sequence are described in detail. By taking hemoglobin, peptide toxin, plant transcription factor, carcinoembryonic antigen, and cytosolic sialidase as examples, sections 4-8 illustrate how to choose alignment method and platform, how to select scoring matrix, how to change gap penalty, how to analyze alignment results and their biological significance. Finally, a simple summary is made. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to explore the molecular mechanism of Apocheima cinerarius response to stress and explore the main associated genes about low temperature and starvation. 【Method】This study cloned and obtained the chitinase gene of A. cinerarius, named AcinCht10（GenBank accession No. : OK504624）, the molecular characteristics and basic physicochemical properties of amino acids of this gene were analyzed, sequence alignment was carried out and phylogenetic tree was constructed. And the expression profile of this gene under stress（low temperature and starvation） was analyzed. 【Result】The predicted molecular formula of AcinCht10 gene was C5017H7689N1349O1490S39, the length of coding protein region was 2967 bp, encoding a total of 988 amino acids, the predicted molecular weight of AcinCht10 was 111. 99 kDa, and the predicted isoelectric point was 6. 25. The hydrophilic coefficient of the protein was-0. 547, and the predicted instability coefficient was 37. 19, indicating that it was stable hydrophilic protein. One signal peptide was found, but no transmembrane structure was found. Two catalytic regions and one chitin binding domain were found. There were 48 serine, 43 threonine and 14 tyrosine phosphoric acid sites, no glycosylation sites were detected. Four phosphoric acid sites were detected. Sequence alignment results showed that the consistency of chitinase gene between AcinCht10 and other Lepidopteran insects was higher than 91%. Phylogenetic results showed that the chitinase genes were grouped into 8 groups（type I-VIII）. AcinCht10 was grouped with Manduca sexta Cht10, Trichoplusia ni Cht10, and Ostrinia furnacalis Cht10, which were also lepidoptera. The results of gene expression analysis showed that AcinCht10 gene expression decreased with the increase of starvation treatment time, and there was no significant difference between adjacent treatments. The expression of AcinCht10 gene was the highest under 25 ℃, while the expression of AcinCht10 gene was at a low level under other temperature stresses with no significant difference. 【Conclusion】AcinCht10 gene was closely related to the response to low temperature and starvation stress. The results are helpful to reveal the molecular function of chitinase gene of A. cinerarius under stress, and lay a foundation for further revealing the molecular mechanism of A. cinerarius response to stress. [ABSTRACT FROM AUTHOR]

Some short peptides can spontaneously self-assemble into various nanostructures via the synergistic driving forces of non-covalent interactions. These non-covalent interactions，including electrostatic interaction，hydrogen bonding，aromatic interactions and other non-covalent interactions，are usually highly coupled together. Through rational sequence design and proper modification of short peptide molecules，the driving forces could be regulated purposively，and the nanostructures and morphologies of the self-assemblies could be controlled accordingly，and thus so as to achieve the fabrication of peptide-based supramolecular biomaterials and develop their functions. In this paper，the effects of hydrogen bonding，π - π stacking， electrostatic interaction，hydrophobic interaction，metal ion coordination and chiral center on the selfassembly behavior of peptide self-assembly have been reviewed. The driving force regulation strategies， including sequence design，pH and concentration adjustment and metal ion coordination，and the resulted nanostructures have also been discussed. We also make the outlooks on the development of peptide-based supramolecular biomaterials with specific functions in biomedicines and biocatalysis. [ABSTRACT FROM AUTHOR]

Post-translational modification of proteins is complex and diverse, with the phosphorylation regulated by kinases and phosphatases being one of the most widespread and important modifications. Dynamic change of quantitative analysis of phosphorylated proteins is helpful to clarify the mechanism of phosphorylation regulating life activities and understand its role in achieving biological functions. Mass spectrometry is the most commonly used strategy for the quantitative analysis of post-translational modification, involving label-free quantification, internal standard absolute quantification, and chemical labeling, etc. In this paper, a chemical labeling approach which has been used for protein glycosylation profiling was applied to the relative quantitative analysis of phosphopeptides. Using the method, carboxyl groups were located on the side chain of aspartic acid and glutamic acid residues, and the C-terminus of peptide were allowed to react with dimethylamine (d0-DMA)/deuterated dimethylamine (d6-DMA). As a result, the carboxyl groups were neutralized, and all enzymatic peptides were labeled with light/heavy tags. After the samples with different tags were mixed, the phosphopeptides were enriched using TiO2 magnetic particles and then analyzed qualitatively and relatively quantitatively by liquid chromatography-mass spectrometry (LC-MS). Amidation could shield the negatively charged carboxyl groups of non-phosphorylated and phosphorylated peptides, so that the peptides with phosphate groups mainly exhibited negative charge property, thus improving the enrichment specificity of TiO2 for phosphopeptides as well as its detection sensitivity in LC-MS analysis. Using 0.2 mg casein as a standard, 8 phosphopeptides were detected in the derivatized samples. A high abundance of b and y ions indicated that the amidation by dimethylamine was highly specific and usually occurs only at the carboxyl group without a significant effect on the phosphate group of peptides. A series of molar ratios (5∶1, 2∶1, 1∶1, 1∶2, 1∶5) of samples were derivatized using d0-DMA and d6-DMA, respectively. The results showed that the error was less than 20% for each ratio, indicating that the method possessed good relative quantitative range and accuracy. However, too many derivative sites in the peptides could result in incomplete derivatization, and the C-terminal lysine residues might self-condense to form lactam during the derivatization process. By selecting some individualized proteases during protein digestion, such as GluC, the number of derivative sites might be in an appropriate range and lysine residue could be avoided at the terminal of peptides, which should be useful for improving identification efficiency and quantitative accuracy of phosphopeptides. In summary, the chemical labeling method based on dimethylamine derivatization presents advantages for high-throughput relative quantitative analysis of phosphopeptides and it is expected to be a powerful tool for protein phosphorylation profiling in biological tissues. [ABSTRACT FROM AUTHOR]

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, and its incidence rate is increasing worldwide. At present, there are still some limitations in the diagnosis and treatment of GDM. It is difficult to find and adjust the unhealthy lifestyle before or in the early pregnancy period to avoid the occurrence and development of GDM. Endogenous polypeptides is a class of life regulating substances that exist in organisms. They have the advantages of low molecular weight, high activity and easy to synthesize and modificate. As a good molecular basis for drugs, they are becoming a research hotspot in recent years. More and more studies have shown that endogenous peptides plays an important role in the prediction, diagnosis and treatment of diseases, and their research in GDM has attracted more and more attention. This paper aims to review the research progress of GDM related peptides. [ABSTRACT FROM AUTHOR]

[ Objective] This paper aimed to overcome the easy breakdown of conventional disease resistant plants. [ Method] A new kind of transgenic rice plant5 was generated based on Host Induced Gene Silencing ( HIGS) technology. [Results] SEC11, a key subunit of signal peptide complex in Magnaporthe oryzae, was selected for generating the HIGS expression vector by gateway technology. HIGS vector was transferred into the Japonica rice cultivar Nipponbare by agrobacterium mediated transformation to obtain transgenic rice plants. The spray assay with conidia of rice blast indicated that the HIGS transgenic rice plants were improved in rice blast resistance. [Conclusion] This study lays the foundation for molecular breading of rice blast resistant varieties with HIGS technology. [ABSTRACT FROM AUTHOR]

Tilia tuan honey has many biological activities, and the source of biological activities is inseparable from the protein and peptides in tilia tuan honey. Antioxidant activity is one of the many biological activities of tilia tuan honey. In this paper, the composition and structure of trypsinolysis peptides in tilia tuan honey were identified by ultra.high performance liquid chromatography.quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UPLC.Q.Exactive), and the relationship between trypsinolysis peptides in tilia tuan honey and antioxidant activity was discussed. Tilia tuan honey protein was precipitated by 20%trichloroacetic acid and lyophilized. The lyophilized protein was dissolved in 100 mmol/L NH4HCO3 buffer solution. Dithiothreotol was added to reduce protein, iodoacetamide was added to alkylate protein, and 500 mmol/L dithiothreotol solution was added to the final protein solution to stop the alkylation reaction, then the protein was hydrolyzed by trypsin. The enzymatic peptides was enriched and purified by C18 solid phase extraction column. Gradient elution was carried out with 0.1% formic acid (A) and acetonitrile (B) as mobile phase. The enzymatic hydrolyzed tilia tuan honey peptides was identified by Full MS/ddMS2 mode of high resolution mass spectrometry (Q.Exactive). The results of mass spectrometry were analyzed by MaxQuant software, and compared on Uniprot by Blast. A total of 52 peptides in tilia tuan honey were identified, 7115% of which were derived from major royal jelly proteins (MRJPs), and the identified peptides belonged to 10 proteins, of which 6 (60%) were MRJP family proteins. Reproducibility analysis of tilia tuan honey peptides mass spectrometry results, more than two repetitive mass spectrometry can achieve reliable identification of tilia tuan honey peptides (871%). According to the structure.activity relationship of honey peptides reported in the literature, 11 peptides with antioxidant activity were screened out. Four different antioxidant activities were tested after chemical synthesis of 11 peptides. The results showed that the antioxidant activities of these 11 peptides were significantly different, and 1 g/L VIYEWK showed strong 2,2′.azinobis.(3.ethylbenzthiazoline.6.sulphonate) (ABTS) free radical scavenging activity (33.8±0.6%), 2,2.diphenyl.1.picryhydrazyl (DPPH) free radical scavenging activity (96.5±0.0%), and showed a certain reducing power(0.010±0.001) and Fe2+ chelating activity (40±02%). The method can quickly and effectively identify the structure of tilia tuan honey peptides, provide a basis for revealing the relationship between tilia tuan honey peptides structure and antioxidant activity. But the results of antioxidant activity in vitro can not fully explain the antioxidant activity of peptides. Therefore, it is necessary to study the antioxidant activity of peptides in vivo and the antioxidant activity of peptides is the result of the interaction of various amino acids. The modification of amino acids of antioxidant peptides can be considered to determine the specific amino acids that play an antioxidant role. [ABSTRACT FROM AUTHOR]

Circular RNA ( circRNA) is a type of endogenous RNA widely expressed in eukaryotic cells, which is formed by back-splicing of pre-RNA without 5'cap and 3'tail. circRNA has long been considered to be without coding ability, for it cannot encode protein and just regulates gene expression as microRNA sponge. However, with more and more research results on circRNA over the years, a small number of circRNAs has been proved able to encode protein or peptides in cap-independent manner. These proteins or peptide have been shown to play a vital role in cellular processes. This paper reviews the current circRNA research, and summarizes some bioinformatics methods related to circRNA protein coding ability. [ABSTRACT FROM AUTHOR]

Traumatic brain injuries(TBI) have caused severe injuries and deaths all over the world, but so far researchers have not found an effective drug in treating TBI on clinic. However, peptides have gradually been in a hot research with its advantages which include safety and tolerance etc. The neuroprotective and anti-inflammatory effects of several peptide compounds in traumatic brain injury are reviewed in this paper. [ABSTRACT FROM AUTHOR]