Ferrier B M, Branda L A
Can J Biochem. 1976 May;54(5):507-11. doi: 10.1139/o76-073.
The first reported synthetic analogue of a naturally occurring peptide with a residue of L-3,4-dihydroxyphenylalanine (L-DOPA) was prepared by coupling N-carbobenzoxy-S-benzylcysteinyl-L-DOPA azide with isoleucylglutaminylasparaginyl-S-benzylcysteinylprolylleuclglycinamide. The protecting groups were removed from the resultant nonapeptide derivative by sodium in liquid ammonia and the peptide analogue was formed by short term oxidation of the dithiol-containing compound. It was isolated by sequential partition chromatography and exclusion chromatography on Sephadex G-25. It was unstable at neutral or alkaline pH. [2-L-DOPA]-oxytocin was found to possess a minimum milk-ejection-like activity of 54 +/- 9 U/mg and uterotonic activity of 26 +/- 4 U/mg. These potencies are approximately 12% and 5% of the corresponding potencies of oxytocin.
首个被报道的含有L-3,4-二羟基苯丙氨酸（L-DOPA）残基的天然存在肽的合成类似物，是通过将N-苄氧羰基-S-苄基半胱氨酰-L-DOPA叠氮化物与异亮氨酰谷氨酰胺基天冬酰胺基-S-苄基半胱氨酰脯氨酰亮氨酰甘氨酰胺偶联制备而成。通过在液氨中用钠去除所得九肽衍生物上的保护基团，并通过对含二硫醇的化合物进行短期氧化形成肽类似物。通过在Sephadex G-25上的连续分配色谱法和排阻色谱法对其进行分离。它在中性或碱性pH下不稳定。发现[2-L-DOPA]-催产素具有最低的类似排乳活性，为54±9 U/mg，子宫收缩活性为26±4 U/mg。这些效价分别约为催产素相应效价的12%和5%。
