Lichliter W D, Naider F, Becker J M
Antimicrob Agents Chemother. 1976 Sep;10(3):483-90. doi: 10.1128/AAC.10.3.483.
The growth of Candida albicans WD 18-4, a methionine and lysine double auxotroph, on a variety of methionine- and lysine-containing peptides was determined. This yeast does not excrete extracellular peptidases. Thus, the growth response to peptides containing the required amino acid is a measure of peptide transport. A variety of methionine-containing peptides such as Met-Met, Met-Met-Met, and Met-Met-Met-Met-Met are transported. Acylation of the N-terminus of transported peptides does not affect their transport, but derivitization of the C-terminus prevents peptide uptake. In contrast, all lysine-containing peptides tested, except Lys-Gly, were not growth substrates. The inability of a peptide to substitute for the requisite amino acid was not due to the absence of cellular peptidases or to toxicity of the nonutilized peptides. Several potentially toxic amino acids were carried into Candida as a component of transported peptides. This establishes the peptide transport system as a possible tool for the design of antibiotics for Candida albicans.
对甲硫氨酸和赖氨酸双营养缺陷型白色念珠菌WD 18 - 4在多种含甲硫氨酸和赖氨酸的肽上的生长情况进行了测定。这种酵母不分泌细胞外肽酶。因此，对含有所需氨基酸的肽的生长反应是肽转运的一种衡量指标。多种含甲硫氨酸的肽，如Met - Met、Met - Met - Met和Met - Met - Met - Met - Met均可被转运。被转运肽的N端酰化不影响其转运，但C端衍生化会阻止肽的摄取。相比之下，除Lys - Gly外，所有测试的含赖氨酸的肽都不是生长底物。一种肽不能替代必需氨基酸并非由于细胞内肽酶的缺失或未利用肽的毒性。几种潜在有毒的氨基酸作为被转运肽的组成部分被带入白色念珠菌。这确立了肽转运系统作为设计白色念珠菌抗生素的一种可能工具。
