Radical acylation of L-lysine derivatives and L-lysine-containing peptides by peroxynitrite-treated diacetyl and methylglyoxal
作者:R. Tokikawa、C. Loffredo、M. Uemi、M. T. Machini、E. J. H. Bechara
DOI:10.3109/10715762.2013.871386
日期:2014.3
alpha-dicarbonyls such as diacetyl, methylglyoxal, 3-deoxyglucosone, and4,5-dioxovaleric acid have been characterized as secondary catabolites that can aggregate proteins and form DNA nucleobase adducts in several human maladies, including Alzheimer's disease, rheumatoid arthritis, diabetes, sepsis, renal failure, and respiratory distress syndrome. In vitro, diacetyl and methylglyoxal have also been shown to rapidly
具有高度亲电性的α-二羰基化合物,例如二乙酰基,甲基乙二醛,3-脱氧葡萄糖苷和4,5-二氧戊酸,已被表征为可在多种人类疾病中聚集蛋白质并形成DNA核碱基加合物的次级分解代谢产物,包括阿尔茨海默氏病,类风湿性关节炎,败血症,肾衰竭和呼吸窘迫综合征。在体外,二乙酰基和甲基乙二醛也已显示出迅速添加过氧亚硝酸盐阴离子(k2〜10(4)-10(5)M(-1)s(-1)),有效的生物亲核试剂,氧化剂和亚硝化剂然后通过可修饰氨基酸的乙酰基中间体将碳链裂解为羧酸。在这项研究中,我们使用了氨基酸衍生物Ac-Lys-OMe和Z-Lys-OMe合成了四肽H-KALA-OH,Ac-KALA-OH,和HK(Boc)ALA-OH揭示由α-二羰基/过亚硝酸盐系统生成的酰基靶向的优先Lys氨基。反应的pH值呈钟形,峰值约为7.5。因此,它们接近ONOOH和催化性H2PO4(-)阴离子的pKa值。反应产物的RP-HPLC和