Romeo D, Skerlavaj B, Bolognesi M, Gennaro R
Department of Biochemistry, Biophysics, and Macromolecular Chemistry, University of Trieste, Italy.
J Biol Chem. 1988 Jul 15;263(20):9573-5.
Cytoplasmic granules of neutrophils store a variety of cationic polypeptides, which exert in vitro a potent antibacterial action and are potentially involved in host defense mechanisms. From an acid extract of bovine neutrophil granules we have purified over 2,000-fold a dodecapeptide exhibiting bactericidal activity against both Escherichia coli and Staphylococcus aureus at 10(-7)-10(-5) M concentration. The purification procedure involved only two steps of ion-exchange and reversed-phase chromatography. The peptide, named bactenecin, has the amino acid sequence, Arg-Leu-Cys-Arg-Ile-Val-Val-Ile-Arg-Val-Cys-Arg, maintained in a cyclic structure by a disulfide bond between the two cysteine residues. Computer modeling of the dodecapeptide resulted in a conformation in which the chain adopts an antiparallel extended structure forming a gamma turn at residue 7.
中性粒细胞的细胞质颗粒储存着多种阳离子多肽，这些多肽在体外具有强大的抗菌作用，并可能参与宿主防御机制。我们从牛中性粒细胞颗粒的酸性提取物中纯化出一种十二肽，其浓度在10^(-7)-10^(-5) M时对大肠杆菌和金黄色葡萄球菌均具有杀菌活性，纯化倍数超过2000倍。纯化过程仅涉及离子交换和反相色谱两个步骤。该肽名为杆菌杀菌肽，其氨基酸序列为Arg-Leu-Cys-Arg-Ile-Val-Val-Ile-Arg-Val-Cys-Arg，通过两个半胱氨酸残基之间的二硫键维持在环状结构中。对该十二肽进行计算机建模，得到一种构象，其中链采用反平行伸展结构，在第7位残基处形成一个γ转角。
