Leonova L, Kokryakov V N, Aleshina G, Hong T, Nguyen T, Zhao C, Waring A J, Lehrer R I
Department of Medicine, UCLA School of Medicine, UCLA, Los Angeles, California 90095-1690, USA.
J Leukoc Biol. 2001 Sep;70(3):461-4.
We purified two new minidefensins (RTD-2 and RTD-3) from the bone marrow of rhesus monkeys. Both were circular octadecapeptides that contained three intramolecular disulfide bonds and were homologous to RTD-1, a circular (theta) defensin previously described by Tang et al. (Science, 286, 498-502, 1999). However, whereas the 18 residues of RTD-1 represent spliced nonapeptide fragments derived from two different demidefensin precursors, RTD-2 and -3 comprise tandem nonapeptide repeats derived from only one of the RTD-1 precursors. Thus, circular minidefensins are products of a novel posttranslational system that generates effector molecule diversity without commensurate genome expansion. A system wherein two demidefensin genes can produce three circular minidefensins might allow n such genes to produce (n/2)(n+1) peptides.
我们从恒河猴的骨髓中纯化出了两种新的微型防御素（RTD - 2和RTD - 3）。它们都是环状十八肽，含有三个分子内二硫键，并且与RTD - 1同源，RTD - 1是Tang等人（《科学》，286卷，498 - 502页，1999年）之前描述过的一种环状（θ）防御素。然而，RTD - 1的18个残基代表了源自两种不同半防御素前体的剪接九肽片段，而RTD - 2和 - 3则由仅源自RTD - 1前体之一的串联九肽重复序列组成。因此，环状微型防御素是一种新型翻译后系统的产物，该系统能在不相应增加基因组的情况下产生效应分子多样性。一个由两个半防御素基因可产生三种环状微型防御素的系统，可能会使n个这样的基因产生(n/2)(n + 1)种肽。
