Moscarello M A, Pang H, Pace-Asciak C R, Wood D D
Division of Biochemistry, Hospital for Sick Children, Toronto, Canada.
J Biol Chem. 1992 May 15;267(14):9779-82.
Peptide 1-21, generated by cyanogen bromide cleavage of each of two highly purified components of human myelin basic protein, components 1 and 8, gave a series of peaks in the fast atom bombardment mass spectra with m/z 2299, 2327, 2355, 2383, and 2411, indicating additions of 42, 70, 98, 126, and 154 atomic mass units respectively with m/z 2327 and 2355 as the dominant species. The pentafluorobenzyl esters prepared from an acid hydrolysate analyzed by negative ion chemical ionization gas chromatography mass spectrometry confirmed that C6, C8, and C10 fatty acids were present. These data demonstrated (i) that the N terminus of a myelin basic protein is not simply acetylated but contains C2, C4, C6, C8, and C10 fatty acids with C4 and C6 as the dominant species, (ii) the two components studied (C-1 and C-8) showed different relative amounts of C2 and C8 in particular, and (iii) human myelin basic protein is the first protein to be reported with a complex N terminus consisting of several alkyl carboxylic acid species.
通过溴化氰裂解人髓鞘碱性蛋白的两种高度纯化组分（组分1和组分8）所产生的肽1-21，在快原子轰击质谱中给出了一系列峰，质荷比分别为2299、2327、2355、2383和2411，表明分别添加了42、70、98、126和154个原子质量单位，其中以质荷比2327和2355的峰为主。由酸水解产物制备的五氟苄基酯经负离子化学电离气相色谱-质谱分析证实存在C6、C8和C10脂肪酸。这些数据表明：（i）髓鞘碱性蛋白的N端并非简单地被乙酰化，而是含有C2、C4、C6、C8和C10脂肪酸，其中以C4和C6为主；（ii）所研究的两种组分（C-1和C-8）尤其在C2和C8的相对含量上有所不同；（iii）人髓鞘碱性蛋白是首个被报道的具有由几种烷基羧酸组成的复杂N端的蛋白质。
