富含甘氨酸抗菌肽的研究进展

抗菌肽是机体先天免疫的重要组成部分,种类繁多。其中富含甘氨酸抗菌肽广泛存在于多种生物体,具有广谱抗菌活性,并且在药物治疗、农业、食品业等方面已经取得一定成绩,该文根据近年抗菌肽研究成果,综述了富含甘氨酸抗菌肽的分类、作用机制、存在的问题和应用前景。     

变温对水生动物生长影响的研究进展

综述了昼夜温度波动对水生动物生长影响的研究概况,其中包括变温研究涉及的实验动物种类、温度设置、变温对生长的影响、变温促长的机制,以及目前存在的问题和应用前景等.     

家蚕抗菌肽的特性与应用

家蚕抗菌肽是在抗菌、抗病毒和抗肿瘤方面具有重要的潜在应用价值的活性肽。家蚕抗菌肽抗菌谱广,由于抗菌肽有普通抗生素所不具有的一系列优点。其研究已经成热点。该文综述了冢蚕抗菌肽理化性质、结构与功能、作用机埋以及应用前景。     

生态考核指标: 水生动物种类指数

为满足关于建立长江流域水生态考核机制的国家需求, 文章构建了水生动物种类指数。该指数以鱼类和底栖动物等动物的种数和重要类群的资源量为评价参数, 以同类水体可达的最高水平或评价元年数据为参照。与多参数指数和预测模型等常用的生态健康评价方法相比, 水生动物种类指数法有简单易行的特点, 便于全面推广应用。     

两栖类动物Cathelicidins家族 抗菌肽研究进展

两栖类动物皮肤裸露和湿润的特性易于微生物的生长,它们为了抵御病原微生物的侵袭,在长期自然进化过程中形成了以抗菌肽(AMPs)为主要防御机制的免疫系统。抗菌肽广泛分布于动物、植物、微生物中,是生物用于抵御细菌、真菌、病毒和原虫等病原体侵袭的重要武器之一,在进化上是一类非常古老而有效的天然防御物质。Cathelicidins是脊椎动物特有的重要抗菌肽家族之一,除具有高效广谱的抗菌活性,还具有如抗炎、抗氧化、伤口修复、抑制组织损伤和促进血管生成等多种重要活性,因此Cathelicidins家族抗菌肽已成为抗感染多肽类新药的研发热点。本文将从两栖类动物Cathelicidins家族抗菌肽的一般特点、来源分布、生物合成与结构、生物学活性、作用机制及应用前景等几个方面,综合阐述国内外的研究动态。     

超声波遥测在水生动物生态学研究中的应用

超声波遥测应用于水生动物是基于海洋生物学家对自然环境中海洋动物的行为和生理研究的迫切需求而诞生的。目前已发展成为包括鱼类、甲壳类、豚类以及海龟等水生动物生态学研究的主要手段之一。本文回顾了超声波遥测应用于水生动物近50年来的发展历程,介绍了该技术的系统组成和使用方法,阐述了该技术的应用范围,分析了其应用于水生动物遥测所面临的问题,提出了相应建议和应用前景。     

昆虫抗菌肽对病原微生物作用的研究进展

在诱导和非诱导情况下,昆虫能产生各种类型的具有体液免疫功能的小分子物质-抗菌肽,参与机体对入侵病原微生物的免疫应答反应,构成了机体独特的免疫系统和免疫机制。这类抗菌肽或抗菌蛋白也存在于其它动物。研究表明,抗菌肽对细菌、真菌、病毒和原虫都具有作用,甚至对癌细胞也具有杀伤作用。随着抗菌肽家族的不断扩大,其结构研究的深入,相继提出了一些崭新的杀菌方式和作用机制。本文从目前国内外这方面的研究入手,分析各抗菌肽的作用特点、杀菌作用模式,展望了基因工程及临床应用的前景。     

抗菌肽临床应用前景分析

抗菌肽是生物天然免疫的重要组成部分,几乎存在于所有种类的生物中。目前已发现的抗菌肽超过2 000种。抗菌肽具有广谱抗菌活性,对大多数革兰氏阳性菌、革兰氏阴性菌和真菌具有强大的抑制作用（包括多药物耐受微生物）,而且这种作用具有较好的选择性。这些特点使抗菌肽具有成为抗感染药物的重大潜力;但抗菌肽的临床应用也面临着一些困难,如抗菌肽大量生产、体内稳定性、微生物耐受等。对抗菌肽临床应用面临的问题及正在进行临床研究和临床前研究的抗菌肽做一简要综述。     

综述人工合成型抗菌肽及其药学应用研究进展

天然抗菌肽（antimicrobial peptides, AMPs）是一类小分子阳离子多肽,具备多种杀菌机制,呈现出高效、广谱的杀菌特性,在抑制耐药性细菌、制备新型抗菌素等方面具有重要的研究价值。以天然抗菌肽为蓝本,设计和开发的人工合成型抗菌肽可以有效克服天然抗菌肽对蛋白酶敏感、细胞毒性较大、生产成本高等缺陷,作为抗感染的潜在药物具有更广阔的应用前景。综述了目前主要的抗菌肽人工改造技术,包括化学修饰法、蛋白质工程技术、计算机分子模拟技术和从头设计最小化抗菌肽方法的研究进展,并对人工合成抗菌肽作为抗菌药物的应用现状进行了简介。     

蛙科两栖动物皮肤抗菌肽的分子多样性及功能

摘要: 蛙科(Ranidae)是全球分布最广泛的两栖动物, 种类超过650种。为开拓和适应广阔的栖息地及多样的生态环境, 其皮肤腺体中进化产生了结构复杂、种类繁多的抗菌肽。它们除具有广谱抗菌活性外, 还有抗肿瘤、抗病毒等生物学活性。蛙科动物皮肤抗菌肽起源于共同祖先, 在漫长的进化过程中, 基因发生了多重复制和突变, 形成了天然抗菌肽的巨大资源库。这些肽在模拟膜的溶剂中几乎都是疏水的, 并带正电荷, 以一种两亲性的α-螺旋的构象存在。根据氨基酸组成及结构的相似性, 可以将蛙科动物抗菌肽分成brevinin-1、esculentin-1、esculentin-2、temporin、ranalexin、ranatuerin-1、ranatuerin-2、plaustrin、brevinin-2、tigerinin、japonicin、nigrocin和melittin相关肽等若干个家族。文章结合作者的研究工作, 综述了目前已经鉴定的蛙科动物皮肤抗菌肽的分子多样性特点、家族性质和生物学活性的研究进展, 并阐述了东北林蛙新家族抗菌肽的特点。 关键词: 蛙科; 抗菌肽家族; 分子多样性; 生物学活性     

Interaction of aurein 1.2 and its analogue with DPPC lipid bilayer

Antibacterial peptides have potential as novel therapeutic agents for bacterial infections. Aurein 1.2 is one of the smallest antibacterial peptides extracted from an anuran. LLAA is a more active analogue of aurein 1.2. Antibacterial peptides usually accomplish their function by interacting with bacterial membrane selectively. In this study, we tried to find the reasons for the stronger antibacterial activity of LLAA compared with aurein 1.2. For this purpose, the interaction of aurein 1.2 and LLAA with dipalmitoylphosphatidylcholine (DPPC) was investigated by molecular dynamics (MD) simulation. In addition, the structure of peptides and their antibacterial activity were investigated by circular dichroism (CD) and dilution test method, respectively. MD results showed that LLAA is more flexible compared with aurein 1.2. Furthermore, LLAA loses its structure more than aurein 1.2 in the DPPC bilayer. A higher amount of water molecules penetrate into bilayer in the presence of LLAA relative to aurein 1.2. According to the antibacterial result that indicated LLAA is remarkably more active than aurein 1.2, it can be concluded that flexibility of the peptide is a determining factor in antibacterial activity. Probably, flexibility of the peptides facilitates formation of effective pores in the lipid bilayer.     

Structural features of helical antimicrobial peptides: their potential to modulate activity on model membranes and biological cells

Antibacterial, membrane-lytic peptides belong to the innate immune system and host defense mechanism of a multitude of animals and plants. The largest group of peptide antibiotics comprises peptides which fold into an amphipathic alpha-helical conformation when interacting with the target. The activity of these peptides is thought to be determined by global structural parameters rather than by the specific amino acid sequence. This review is concerned with the influence of structural parameters, such as peptide helicity, hydrophobicity, hydrophobic moment, peptide charge and the size of the hydrophobic/hydrophilic domain, on membrane activity and selectivity. The potential of these parameters to increase the antibacterial activity and to improve the prokaryotic selectivity of natural and model peptides is assessed. Furthermore, biophysical studies are summarized which elucidated the molecular basis for activity and selectivity modulations on the level of model membranes. Finally, the knowledge about the role of peptide structural parameters is applied to understand the different activity spectra of natural membrane-lytic peptides.     

水产动物抗菌肽的研究进展

抗菌肽广泛分布于多种生物,具有分子量小、耐热、广谱抗菌等特性。它在杀菌过程中不易产生耐药性,使其具有潜在的医药价值。本文综述了水产动物抗菌肽的结构特征、生物学活性、抗菌机制、目前克隆的基因的结构与功能,以及在免疫防御中的表达等一系列问题。     

抗菌肽SMAP-29结构功能及分子设计策略

抗菌肽是生物体内产生的一种具有生物活性的小分子多肽,具有广谱抗细菌、抗病毒、抗真菌甚至抗癌作用。SMAP-29是来源于绵羊骨髓细胞,包含29个氨基酸的Cathelicidin类α-螺旋结构抗菌肽。SMAP-29具有多种生物活性,包括抗革兰氏阳/阴性菌、抗真菌、抗病毒、抗寄生虫、抗螺旋体、抗衣原体和中和内毒素活性,并且具有作用机制独特、快速杀灭细菌的特点。以下综述了SMAP-29抗菌肽家族的基因和蛋白结构、结构与活性关系、作用机制、生物功能、基因重组表达,重点阐述了SMAP-29结构、分子设计的必要性和基于     

绵羊抗菌肽研究进展

抗菌肽是动植物先天性免疫系统的组成部分。概述了绵羊抗菌肽Defensin、Cathelicidins、SAAPs的研究进展和应用前景,并分析了在绵羊抗菌肽研究中存在的问题。     

The terminal structure plays an important role in the biological activity of cecropin CMIV

Antibacterial peptides have received increasing attention as a new pharmaceutical substance. But the molecular mechanism of lysis is still poorly understood. CMIV gene and mutant CMIV gene in GST fusion system were expressed. After cleaving with different cleavage reagents, the peptide with an excess of N-terminus and with an un-amidated C-terminus stopped the activity while the peptide with an excess Asn at the C-terminus had the activity level the same as natural CMIV. The results showed that the terminal structure of cecropin CMIV played an important role in its biological activity.     

The terminal structure plays an important role in the biological activity of cecropin CMIV

Antibacterial peptides have received increasing attention as a new pharmaceutical substance. But the molecular mechanism of lysis is still poorly understood. CMIV gene and mutant CMIV gene in GST fusion system were expressed. After cleaving with different cleavage reagents, the peptide with an excess of N-terminus and with an un-amidated C-terminus stopped the activity while the peptide with an excess Asn at the C-terminus had the activity level the same as natural CMIV. The results showed that the terminal structure of cecropin CMIV played an important role in its biological activity.     

凡纳对虾对虾素基因的克隆与抗菌性质分析

目的:抗菌肽分子在无脊椎动物的先天免疫系统中,发挥着重要的抗菌作用;为了不断完善无脊椎动物先天免疫系统的抗菌机制,作者以凡纳对虾的对虾素基因作为研究对象,进行分子生物学方面研究。方法:以凡纳对虾的对虾素基因———penaeidin 4抗菌肽基因(Lva-pen 4)作为研究对象,主要进行了基因克隆、氨基酸序列比对、系统进化关系分析以及分子结构初步预测等研究内容。结果:Lva-pen 4的cDNA序列全长624bp,开放阅读框包括204bp,演绎67个氨基酸残基;在Lva-pen 4分子一级结构的氨基酸序列中,存在一个对虾素结构域,其中包括8个保守存在的半胱氨酸残基和6个脯氨酸残基。结论:根据分子结构的分析结果,推测Lva-pen 4是一个重要的免疫反应相关基因,在先天免疫系统中发挥着重要作用。     

The molecular design of a recombinant antimicrobial peptide CP and its in vitro activity

Antibacterial peptides from various sources express different antibacterial activity. In order to obtain a high activity antibacterial peptide, the sequences of four antimicrobial peptides--Protegrin-1, 4 kDa Scorpion Defensin, Metalnikowin-2A and Sheep Myeloid Antibacterial Peptide SMAP-29--were exploited to generate a synthetic antimicrobial peptide cp gene, which was then cloned into the expression vector pPICZalpha-A. The constructed recombinant expression vector pPICZalpha-cp was transformed into Pichia pastoris X-33, in which the synthetic antimicrobial peptide (CP) could be expressed under the control of the inducible AOX1 promoter and secreted via the alpha mating factor leader of Saccharomyces cerevisiae. Results showed that recombinant plasmid is highly stable, and In vitro experiments showed that the recombinant antimicrobial peptide CP is heat and acid-stable, and it has high antibacterial activity against several Gram-positive and -negative bacteria. Only 1 microg of the recombinant antimicrobial peptide CP has an antibacterial activity equivalent to 64 U ampicillin. Thus, this recombinant antimicrobial peptide could serve as an attractive candidate for the development of therapeutic antimicrobial drugs.