Amur S G, Shanker G, Cochran J M, Ved H S, Pieringer R A
J Neurosci Res. 1986;16(2):367-76. doi: 10.1002/jnr.490160204.
Sinefungin, a known inhibitor of protein methylation, inhibited the myelin basic protein (arginine) methyltransferase activity in homogenates of cultured cerebral cells from embryonic mice. Fifty percent inhibition was achieved with 25 microM sinefungin. Electron microscopic examination of the myelin fraction, isolated by gradient density centrifugation and obtained from untreated cells, revealed numerous ringlike multilamellar membranous substructures that had a major dense line periodicity, compactness, and the general appearance expected of myelin obtained by the same technique from whole brain. Cells treated with 30 microM sinefungin, which inhibits myelin basic protein methyltransferase in broken cell preparations about 60%, produced ringlike structures that were devoid of multilamellar periodicity and compactness reminiscent of the vacuolated myelin observed in subacute combined degeneration and in nitrous-oxide- or cycloleucine-treated animals in which methyltransferase activity is also inhibited. The sinefungin-induced change in multilamellar periodicity cannot be attributed to a lack of myelin basic protein, since the ratio of myelin basic protein to total protein did not decrease in sinefungin-treated cells. This primary culture system should be useful for further evaluating the hypothesis that the methylation of myelin basic protein is related to the formation of compact myelin.
已知的蛋白质甲基化抑制剂西尼芬净抑制了来自胚胎小鼠的培养脑细胞匀浆中髓鞘碱性蛋白（精氨酸）甲基转移酶的活性。25微摩尔的西尼芬净可实现50%的抑制率。通过梯度密度离心分离未处理细胞获得的髓鞘部分的电子显微镜检查显示，有许多环状多层膜状亚结构，具有主要致密线周期性、紧密性以及通过相同技术从全脑获得的髓鞘所预期的一般外观。用30微摩尔西尼芬净处理的细胞，该药物在破碎细胞制剂中可抑制髓鞘碱性蛋白甲基转移酶约60%，产生的环状结构缺乏多层周期性和紧密性，这让人联想到在亚急性联合变性以及在甲基转移酶活性也受到抑制的一氧化二氮或环亮氨酸处理的动物中观察到的空泡化髓鞘。西尼芬净诱导的多层周期性变化不能归因于髓鞘碱性蛋白的缺乏，因为在西尼芬净处理的细胞中，髓鞘碱性蛋白与总蛋白的比例并未降低。这个原代培养系统应该有助于进一步评估髓鞘碱性蛋白甲基化与紧密髓鞘形成相关的假说。
