Rollema H S, Metzger J W, Both P, Kuipers O P, Siezen R J
Department of Biophysical Chemistry, Netherlands Institute for Dairy Research, The Netherlands.
Eur J Biochem. 1996 Nov 1;241(3):716-22. doi: 10.1111/j.1432-1033.1996.00716.x.
Nisin, a 34-residue peptide bacteriocin, contains the less common amino acids lanthionine, beta-methyl-lanthionine, dehydroalanine (Dha), and dehydrobutyrine (Dhb). Several chemically modified nisin A species were purified by reverse-phase HPLC and characterized by two-dimensional NMR and electrospray mass spectrometry. Five constituents, [2-hydroxy-Ala5]nisin, [Ile4-amide,pyruvyl-Leu6]des-Dha5-nisin, [Met(O)21]nisin, [Ser33]nisin, and nisin-(1-32)-peptide amide, were found in a commercial nisin sample. A further species, [2-hydroxy-Ala5]nisin-(1-32)-peptide amide, was obtained by freeze drying an acidic nisin solution. These compounds are formed by chemical modification of nisin: the addition of a water molecule to the dehydroalanine residues, which can lead to the cleavage of the polypeptide chain, or the oxidation of methionine residues. The 2-hydroxyalanine-containing products have a limited stability; they are spontaneously converted into the corresponding des-dehydroalanine derivatives. The growth-inhibiting activity of the modified nisins towards different bacteria was determined. The 2-hydroxyalanine-containing species and the des-dehydroalanine derivative show a strong reduction in biological activity as compared to native nisin. [Met(O)21]nisin and [Ser33]nisin show moderate or no reduction in biological activity.
乳酸链球菌素是一种由34个氨基酸残基组成的肽类细菌素，含有不太常见的氨基酸丙氨酸、β-甲基丙氨酸、脱氢丙氨酸（Dha）和脱氢丁氨酸（Dhb）。通过反相高效液相色谱法纯化了几种化学修饰的乳酸链球菌素A，并通过二维核磁共振和电喷雾质谱对其进行了表征。在市售的乳酸链球菌素样品中发现了五种成分，即[2-羟基-Ala5]乳酸链球菌素、[Ile4-酰胺，丙酮酸-Leu6]去-Dha5-乳酸链球菌素、[Met(O)21]乳酸链球菌素、[Ser33]乳酸链球菌素和乳酸链球菌素-(1-32)-肽酰胺。通过冷冻干燥酸性乳酸链球菌素溶液得到了另一种成分，即[2-羟基-Ala5]乳酸链球菌素-(1-32)-肽酰胺。这些化合物是由乳酸链球菌素的化学修饰形成的：向脱氢丙氨酸残基添加一个水分子，这可能导致多肽链的断裂，或者甲硫氨酸残基的氧化。含2-羟基丙氨酸的产物稳定性有限；它们会自发地转化为相应的去脱氢丙氨酸衍生物。测定了修饰后的乳酸链球菌素对不同细菌的生长抑制活性。与天然乳酸链球菌素相比，含2-羟基丙氨酸的物种和去脱氢丙氨酸衍生物的生物活性大幅降低。[Met(O)21]乳酸链球菌素和[Ser33]乳酸链球菌素的生物活性降低程度适中或未降低。
