AN INTERNAL STANDARD FOR AMINO ACID ANALYSES - S-BETA-(4-PYRIDYLETHYL!-L-CYSTEINE
AN INTERNAL STANDARD FOR AMINO ACID ANALYSES - S-BETA-(4-PYRIDYLETHYL!-L-CYSTEINE
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DOI：
10.1016/0003-2697(70)90211-3
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发表时间：
1970-01-01
影响因子：
2.9
通讯作者：
FRIEDMAN, M
中科院分区：
文献类型：
--
作者：
CAVINS, JF;FRIEDMAN, M
在含三乙胺的水溶液中，L-半胱氨酸与4-乙烯基吡啶反应合成了新的氨基酸S-β-（4-吡啶乙基）-L-半胱氨酸（PEC）。PEC的假定结构通过红外、核磁共振和质谱分析得到证实。PEC在用于蛋白质水解的条件下对酸稳定，其在碱性柱上洗脱为精氨酸之前的离散峰，并且其茚三酮颜色与浓度呈线性关系。新的氨基酸已被评价为氨基酸分析的内标。当PEC在水解之前或之后加入到蛋白质中时，获得了同样优异的结果。在水解前加入PEC消除了对水解产物的氮分析和对色谱柱的准确样品应用的需要。
The new amino acid, S-β-(4-pyridylethyl)-l-cysteine (PEC), was prepared by treating l-cysteine with 4-vinylpyridine in an aqueous medium containing triethylamine. The postulated structure for PEC was confirmed by infrared, nuclear magnetic resonance, and mass spectroscopic analyses. PEC is stable to acid under conditions used for protein hydrolysis, it elutes on a basic column as a discrete peak before arginine, and its ninhydrin color is linear with concentration. The new amino acid has been evaluated as a internal standard for amino acid analyses. Equally excellent results were obtained when PEC was added to the protein either before or after hydrolysis. Addition of PEC before hydrolysis eliminates the need for nitrogen analysis of the hydrolysate and for accurate sample application to the column.