猪源大肠杆菌热稳定肠毒素的一级结构测定

Primary structure determination of Escherichia coli heat-stable enterotoxin of porcine origin.

作者信息

Lazure C, Seidah N G, Chrétien M, Lallier R, St-Pierre S

出版信息

Can J Biochem Cell Biol. 1983 May;61(5):287-92. doi: 10.1139/o83-039.

Abstract

The chemical characterization of Escherichia coli heat-stable enterotoxin (ST) is described. The toxin was isolated and purified to homogeneity from the E. coli strain F11 (PI55) of porcine origin. Following quantitative amino acid analysis, the enterotoxin was found to contain 18 amino acids including 6 cysteines, but was devoid of Ser, Val, Met, Ile, Lys, His, and Arg residues. All cysteine residues were found to be involved in disulfide bridges, even though their positions could not be localized. The enterotoxin thus has a molecular weight of 1979 and was shown to be an octadecapeptide with the following sequence: H2N-Asn-Thr-Phe-Tyr-Cys-Cys-Glu-Leu-Cys-Cys-Asn-Pro-Ala-Cys-Ala-Gly-Cys-Tyr- COOH. Its relationship to other known enterotoxins is discussed.

摘要

本文描述了大肠杆菌热稳定肠毒素（ST）的化学特性。该毒素从猪源大肠杆菌菌株F11（PI55）中分离并纯化至同质。经过定量氨基酸分析，发现该肠毒素含有18种氨基酸，包括6个半胱氨酸，但不含丝氨酸、缬氨酸、甲硫氨酸、异亮氨酸、赖氨酸、组氨酸和精氨酸残基。尽管无法确定半胱氨酸残基的位置，但发现所有半胱氨酸残基都参与了二硫键的形成。因此，该肠毒素的分子量为1979，是一种十八肽，其序列如下：H2N-Asn-Thr-Phe-Tyr-Cys-Cys-Glu-Leu-Cys-Cys-Asn-Pro-Ala-Cys-Ala-Gly-Cys-Tyr-COOH。文中还讨论了它与其他已知肠毒素的关系。