生物活性肽的生理功能及研究进展

随着人们生活水平的提高,伴随现代文明而来的各种富裕病如高血压、高血脂、肥胖病、糖尿病和癌症等越来越引起人们的关注,人们的消费观念已从单纯的吃饱吃好向防病治病方向转变。生物活性肽具有涉及神经、激素和免疫调节、抗血栓、抗高血压、抗胆固醇、抗细菌病毒、抗癌、抗氧化、清除自由基、改善氮素吸收关系和矿质运输、促生长、调节食品风味、口味、硬度等多种生理功能,被誉为21世纪人类健康的新宠儿。简述了生物活性肽的特点、生理功能及其研究进展。     

乳清蛋白及其生物活性肽血压调节功能研究进展

乳清蛋白既是优质蛋白来源,也是抗高血压生物活性肽的理想来源,开发具有调节血压功效的蛋白多肽类产品对未来临床高血压防治将发挥重要作用。文章综述了乳清蛋白生物活性肽血压调节功能的基本机制和研究现状,并对其未来发展趋势和应用前景进行了讨论。     

乳清蛋白生物活性肽研究进展

以乳清蛋白为原料,经过酶解或发酵等方法可以获得独特理化性质的生物活性肽。乳清蛋白生物活性肽来源广、活性强、分子量小,在食品和医药行业有很高的应用研究价值,已经成为研究热点。随着制备、分离纯化以及鉴定技术的不断发展和成熟,越来越多的乳清蛋白生物活性肽被发现。本研究主要综述了乳清蛋白生物活性肽的制备、分离纯化、鉴定方法以及生物功能,并展望了乳清蛋白生物活性肽应用前景,以期为功能性乳清蛋白生物活性肽产品的开发与应用提供参考。     

核桃肽生物活性的研究进展

综述了核桃肽的提取工艺及其抗氧化、抗疲劳、降血糖、免疫调节等生物活性。     

噬菌体展示的豆蔻酰转移酶抑制肽序列结构和功能研究

对一个具有很强的抑制豆蔻酰转移酶活性的抑制肽噬菌体所展示的随机区１５肽序列ＴＷＰＶＶＨＧＡＣＲＡＨＧＨＣ进行关键氨基酸残基的单点,双点和缺失等一系列突变研究,以确定其功能区段。结果显示;Ｗ２Ａ,Ｈ６Ｎ和Ｈ６Ｒ突变抑制活性明显下降,Ｐ３Ａ,Ｖ４Ｖ５→Ｖ４Ａ５双点突变对活性也有一定的影响,而Ｖ４Ｖ５→Ｗ４Ｗ５,Ｈ１２Ｎ,Ｈ１４Ｎ,Ｃ９Ｓ,Ｃ１５Ｓ,ΔＣ１５,ΔＨ１４Ｃ１５和Δ９－Ｃ１５等突变对则基本上     

食源性生物活性肽免疫调节功能的研究

生物活性肽通常用来表示生物进行生命活动过程中起到调控作用的化学物质,它在机体内发挥了一系列作用。肽由相应的蛋白质所组成,在化学上通过电解能够获取蛋白水解物质,对免疫系统具有极大的调节作用。最近,因为其制备的原材料易于获取且其效用都非常显著,科学家们纷纷将调查研究的目光锁定其中。本研究对食源性生物活性肽的吸收机制、常见种类、制备方法以及研究现状进行了综述,并对其发展前景进行了展望。     

乳酪蛋白源生物活性肽的研究进展

酪蛋白是生物活性肽的重要来源,可以通过体内的胃肠消化和食品加工过程中的酶解将其释放出来。乳酪蛋白源的生物活性肽的生物学意义、对人类健康的影响和其在新型功能性食品加工中的作用具有重要的研究价值。     

生物活性肽的辐射防护作用研究进展

对多种生物活性肽的辐射防护作用的研究进展进行了综述,为天然辐射防护剂的研发及临床应用提供科学依据。     

酶法制备海洋活性肽及其功能活性研究进展

海洋生物活性肽(Marine biological active peptide)是从海洋生物中提取的具有优化机体代谢环境、有益于机体健康的一类多肽。酶法制备海洋生物活性肽是目前最常用的制备方法,是通过适当的蛋白酶水解海洋生物蛋白来制备生物活性肽的一种方法。海洋生物活性肽在降血压、抗氧化、抗凝血及抗菌等方面效果显著,对治疗和预防疾病具有巨大潜力。介绍海洋生物活性肽在酶解制备及其生物学功能方面国内外研究进展,为进一步开展海洋活性多肽研究提供参考。     

生物活性低聚肽生理功能的研究进展

相比多肽,低聚肽具有优异的吸收机制与生物活性,本文主要从生物活性低聚肽生理功能的角度综述生物活性低聚肽的研究进展,并对生物活性低聚肽的研究前景进行了展望。     

食物蛋白酶解物中的生物活性肽

本文讨论了食物蛋白质酶解物中的生物活性肽及其药理作用     

The Complete Amino Acid Sequence of Human P2 Protein

Abstract: The complete amino acid sequence of P2 protein from human peripheral nerve myelin was determined from nine staphylococcal protease peptides and four cyanogen bromide peptides. Human P2 protein is composed of 131 amino acids and has a molecular weight of 14,818. Compared to bovine P2 protein, there are replacements at nine positions (human↔bovine): 18(Asp↔Glu), 39(Thr↔Arg), 56(Thr↔Pro), 83(Ile↔Thr), 87(Gln↔Ala), 96(Arg↔Lys), 100(Lys↔Asn), 115 (Ala↔Val), and 121(Gly↔Asp).     

The Amino Acid Sequence of the Tryptophan-Containing Subunit (α-Subunit) of Bovine Brain S-100 Protein

Abstract: The tryptophan-containing subunit (α-subunit) of bovine brain S-100 protein was purified from a S -aminoethyl derivative of S-100a protein, and its amino acid sequence was determined. The α-subunit contained 93 residues, including one tryptophan, and had a molecular weight of 10,400. The sequence shows an extensive homology (58% identity) to the sequence of another "tryptophan-free" subunit (β-subunit) found in both S-100a and S-100b protein, and has a calcium binding site characteristic of the "E-F hand" proteins, such as calmodulin or troponin C. The tryptophan residue is located at position 90 which is presumably adjacent to the C-terminal end of the α-helix following the calcium binding loop, and thus appears likely to serve as a specific probe in structure-function studies of S-100a protein.     

Amino Acid Sequence of Porcine Myelin Basic Protein

The myelin basic protein (BP) of pig brain was cleaved into its constituent tryptic peptides and the amino acid composition of each was determined. Those tryptic peptides that had not been sequenced previously were cleaved with dipeptidyl peptidases and the resulting dipeptides were trimethylsilated, separated by gas chromatography, and identified by mass spectrometry. Carboxypeptidases B and Y were used to establish the COOH-terminal sequences of some of the tryptic peptides; one tryptic peptide (sequence 76-92) was cleaved with thermolysin and the thermolytic peptides were analyzed. From the results of the present study together with those reported previously, it has been possible to determine the complete amino acid sequence of the protein. The protein consists of 172 residues and has a theoretical molecular weight of 18,604. Its amino acid sequence is identical with that reported for the homologous bovine protein with the following exceptions: Ser replaces (bovine) Ala2; His-Gly is inserted between Arg9 and Ser10; Ala replaces Ser45; His and Gly replace Gly76 and His77, respectively; Pro replaces Ser131 and Ser135; Ala is inserted between Gly142 and His143; and Gln replaces His143.     

Shark Myelin Basic Protein: Amino Acid Sequence, Secondary Structure, and Self-Association

Myelin basic protein (MBP) from the Whaler shark (Carcharhinus obscurus) has been purified from acid extracts of a chloroform/methanol pellet from whole brains. The amino acid sequence of the majority of the protein has been determined and compared with the sequences of other MBPs. The shark protein has only 44% homology with the bovine protein, but, in common with other MBPs, it has basic residues distributed throughout the sequence and no extensive segments that are predicted to have an ordered secondary structure in solution. Shark MBP lacks the triproline sequence previously postulated to form a hairpin bend in the molecule. The region containing the putative consensus sequence for encephalitogenicity in the guinea pig contains several substitutions, thus accounting for the lack of activity of the shark protein. Studies of the secondary structure and self-association have shown that shark MBP possesses solution properties similar to those of the bovine protein, despite the extensive differences in primary structure.     

Bioactive properties of milk proteins in humans: A review

Many studies have demonstrated that milk protein consumption has benefits in terms of promoting human health. This review assesses the intervention studies which have evaluated potential health enhancing effects in humans following the ingestion of milk proteins. The impact of milk protein ingestion has been studied to asses their satiating, hypotensive, antimicrobial, anti-inflammatory, anticancer, antioxidant and insulinotropic properties as well as their impact on morphological modifications (e.g., muscle and fat mass) in humans. Consistent health promoting effects appear to have been observed in certain instances (i.e., muscle protein synthesis, insulinotropic and hypotensive activity). However, controversial outcomes have also been reported (i.e., antimicrobial, anti-inflammatory, anticancer and antioxidant properties). Several factors including interindividual differences, the timing of protein ingestion as well as the potency of the active components may explain these differences. In addition, processing conditions have been reported, in certain instances, to affect milk protein structure and therefore modify their bioactive potential. It is thought that the health promoting properties of milk proteins are linked to the release of bioactive peptides (BAPs) during gastrointestinal digestion. There is a need for further research to develop a more in-depth understanding on the possible mechanisms involved in the observed physiological effects. In addition, more carefully controlled and appropriately powered human intervention studies are required to demonstrate the health enhancing properties of milk proteins in humans.     

A Computer Program to Compare Sequence Fingerprints of Homologous Proteins for the Rapid Assessment of Their Primary Structure Differences

We have developed a computer program for the rapid assessment of the primary structure differences between a protein of unknown sequence and a homologous known protein. Both proteins are reduced, alkylated, and digested with the same hydrolytic agent. The unfractionated peptide mixtures are submitted to automatic sequence analysis. Based on the knowledge of the reference sequence, the program utilizes the analysis data to identify all the potential peptides present in the two mixtures, determining their primary structure, homology degree, and molecular weight calculated both as integer MH⁺ and average mass variables. These fingerprints allow the user to easily identify the structural differences between the two proteins and clarify possible doubts by a mass spectrometric analysis of the two mixtures. In order to verify the utility of the program, we provide an application example using the already reported data of two homologous proteins.     

Complete Amino Acid Sequence and Location of Omp-28, an Important Immunogenic Protein from Salmonella enterica serovar typhi

Omp-28 isolated from Salmonella enterica serovar typhi presented a subunit molecular mass of 9,632 Da by MALDI-TOF MS. It was denatured, S-alkylated, and 1) directly submitted to Edman sequencing, 2) cleaved with CNBr, and 3) hydrolyzed either with endoproteinase Glu-C or Asp-N. The major CNBr peptide containing the C-terminal portion of Omp-28 was isolated by tricine-SDS-PAGE and electroblotted whereas Omp-28 enzymatic peptides were isolated by C18-RP-HPLC. All peptides were sequenced. This approach allowed the elucidation of the complete primary structure of Omp-28. Its amino acid sequence is identical to that deduced from part of the DNA of the "putative periplasmic transport protein" of either S. enterica serovar typhimurium and a multiple drug resistant S. enterica serovar typhi. Omp-28 homologous protein sequences were also deduced from Escherichia coli and Yersinia pestis genomic DNA. All proteins had their secondary structures predicted. Immunogold cytochemistry indicated that Omp-28 is found on the bacterium outer membrane.     

大豆Kunitz型胰蛋白酶抑制剂新类型Tid的全序列分析

大豆ｋｕｎｉｔｚ型胰蛋白酶抑制剂（ＳＢＴｉＡ２）是一种大量存在于大豆（Ｇｌｙｃｉｎｅｍａｘ）中的种子贮藏蛋白．虽然对它的生化特性及结构已有较多的研究,但它在体内的主要功能仍不很清楚．国际上所发现的３个由显性等位基因Ｔｉａ、Ｔｉｂ、Ｔｉｃ编码的大豆ｋｕｎｉｔｚ胰蛋白酶抑制剂的氨基酸顺序已被明确测定,相互间有一到多个氨基酸残基的不同［１］．Ｔｉｄ是从我国１５０００余份大豆资源中筛选到的唯一一份ｋｕｎｉｔｚ型胰蛋白酶抑制剂位点的新类型,遗传分析证明它是另一个ＳＢＴｉＡ２的显性等位基因［２,３］．严…     

生物肽降压作用机制及定量构效关系的研究

高血压是心脑血管疾病的首要危险因素,严重威胁着人类的生命健康。生物肽能有效预防和治疗高血压,并且具有安全可靠、作用多靶点等特点。大量的研究表明生物肽存在多种降压作用机制,深入研究降压机制可为中药治疗高血压提供新思路。本文综述了近年来生物肽潜在的降压机制,并探索其定量构效关系,旨在为中药药效组分的研究以及相关药物设计和筛选提供理论指导。