Payne J W
Biochem J. 1971 Jun;123(2):255-60. doi: 10.1042/bj1230255.
Peptides that have an N-terminal proline residue are taken up by Escherichia coli and are degraded by intracellular peptidases. A mutant that is unable to transport oligopeptides with N-terminal alpha-amino acids is also unable to transport the peptides with N-terminal proline. Dipeptides and oligopeptides can prevent the uptake of the corresponding prolyl peptides and the converse competitive interactions are also observed. Although the peptide alpha-amino group is essential to the process of peptide transport, the results with the prolyl peptides indicate that the dipeptide and oligopeptide permeases can handle peptides with either an alpha-amino or alpha-imino group.
具有N端脯氨酸残基的肽可被大肠杆菌摄取，并被细胞内肽酶降解。一个无法转运带有N端α-氨基酸的寡肽的突变体，也无法转运带有N端脯氨酸的肽。二肽和寡肽可以阻止相应脯氨酰肽的摄取，并且也观察到了相反的竞争性相互作用。虽然肽的α-氨基对于肽转运过程至关重要，但脯氨酰肽的实验结果表明，二肽和寡肽通透酶可以处理带有α-氨基或α-亚氨基的肽。
