˙OH radical induced decarboxylation of methionine-containing peptides. Influence of peptide sequence and net charge
作者:Krzysztof Bobrowski、Christian Schöneich、Jerzy Holcman、Klaus-Dieter Asmus
DOI:10.1039/p29910000353
日期:——
The ˙OH radical induced oxidation of methionine-containing peptides results in significantly different decarboxylation yields upon variation of the location of the methionine unit with respect to the terminal functions (Met–Gly, Met–Glu, Met–Gly–Gly, Gly–Met–Gly, Gly–Met and Gly–Gly–Met), or with the nature of neighbouring amino acids located at the N-terminus of methionine (Ala–Met, β-Ala-Met, Val-Met
˙OH自由基诱导的含蛋氨酸肽的氧化会导致蛋氨酸单元位置相对于末端功能(Met–Gly,Met–Glu,Met–Gly–Gly,Gly–Met -Gly,Gly-Met和Gly-Gly-Met),或具有位于蛋氨酸N-末端的相邻氨基酸(Ala-Met,β-Ala-Met,Val-Met,Leu-Met,Ser -Met,Thr-Met,His-Met,γ-Glu-Met,Pro-Met,Gly-Gly-Phe-Met和Tyr-Gly-Gly-Phe-Met)。γ-射线分解测得的CO 2产率从0%(Met–Gly,Met–Glu,Met–Gly–Gly,Gly–Met–Gly和Pro–Met)变化到约80%(γ–Glu–Met)可用的˙OH自由基。从机理上讲,脱羧被认为是通过分子内“外层”电子从甲硫氨酸羧酸盐官能团转移到氧化硫官能团S˙ +。γ-Glu-Met中存在一条额外的N末端脱羧途径,该途