抗菌肽、防御素与消化系统疾病

Antibacterial Peptides,Defensins and Digestive System Disease

抗菌肽(antibacterial peptides)是广泛存在于动、植物体内,具有一定抗菌谱的小分子肽。可参与先天免疫和炎性应答诸多方面,目前已从动、植物等不同物种中分离、纯化出多种抗菌肽,在哺乳动物中发现的抗菌肽主要有防御素(defensins)、cathelicidins和histatins。防御素是普遍分布于哺乳动物、昆虫及植物体内,抗菌谱广,对细菌、真菌、被膜病毒有很强作用的阳离子多肽。根据其结构特征和生物学来源不同,分为:α-防御素、β-防御素、θ-防御素、昆虫防御素、植物防御素等。目前已明确的人类α-防御素有6种,β-防御素主要有4种。抗菌肽、防御素与消化系统疾病,如幽门螺杆菌感染、炎症性肠病、消化道肿瘤的关系已成为研究热点。

Antimicrobial poptides is a micromnlecule peptide having certain antibacterial spectrum which is widely existed in the body of plant and animal, which have been isolated from many bacteria, fungi, plants, invertebrates and vertebrates, are an important component of the natural defenses of most living organisms. A wide variety of human proteins and peptides also have antimicrobial activity and play important roles in innate immunity. Three important groups of human antimicrubial have been found,they are Defensins, Cathelicidins and Histatins.The defensins are nationic non-glycosylated peptides which exhibit broad-spectrum activity against Gram-positive and Gram-negative bacteria, yeasts, fungi and enveloped viruses. Defensins can be subdivided into many classes according to their structural and features differences：the α-defensins, β-defensins, θ-defensins, insects defensins and plants defensins, etc. Six kinds of α-defensins and four kinds of β-defensins are found by now. The relations of antibacterial pepfides and defensins with digestive system disease such as Helieobacter pylori, inflammatory bowel disease and carcinoma are focused recently.