绿臭蛙皮中与神经降压肽有关的绿臭蛙降压肽的分离及其化学和生物学特征

本文利用Sep-Pak Cu和反相HPLC从我国产绿臭蛙皮的甲醇提取物中分得一新的神经降压肽类似物:绿臭蛙降压肽。其结构为Asp-Lys-Arg-Pro-Tyr-Ile-Leu-His-Glu。此结构与神经降压肽羧端部分结构相似。但比后者多出残基His-Glu。相应的合成品与天然肽在高效液相色谱、氨基酸分析和生物测定中均表现一致。此肽对大鼠产生降血压效应,但作用比神经降压肽弱。该肽对豚鼠回肠制品有很强的和可重复的收缩活性,这一点又与两栖动物皮肤中另一神经降压肽类似物——xenopsin的相应活性有别。     

高效液相色谱在生物医药研究中的应用第三讲蛋白质的反相高效液相色谱分离

近十年来,高效液相色谱(HPLC)在蛋白质分离纯化方面取得了很大的进展,并得到了广泛的应用。HPLC包括排阻色谱、离子交换色谱、亲和色谱、疏水反应色谱以及反相色谱等,几乎已在蛋白质分离各种传统方法中得到应用。这些方法在蛋白质分离中各有其地位,但到目前为止人们普遍认为反相高效液相色谱(RP-HPLC是分离纯化蛋白质的最有效的方法     

我国产绿臭蛙的皮肤中一个新的速激肽——绿臭蛙激肽的分离和结构

本文利用Sep—Pak C_(13)和HPLC,从我国产绿臭蛙的皮肤甲醇提取物中分离到一个新的14肽——绿臭蛙激肽。此肽结构经分析定为:Asp—Asp—Ala—Ser—Asp—Arg—Ala—Lys—Lys—Phe—Tyr—Gly—Leu—Met—NH_2,且为化学合成所证明。此肽是两栖动物速激肽中最长的一个,其N-端氨基酸与速激肽类其它肽的相应部分有很大区别。此外,简要讨论了纯化过程中绿臭蛙激呔亚砜的形成及其色谱峰的分裂。     

农抗101-己及庚的分离及结构

农抗101是从制霉菌素产生菌金色链霉菌A-94菌株发酵液中得到的抗真菌油状物.经逆流分溶和分部结晶等方法从农抗101中分到了八个成分,农抗101-己及庚为其中两个成分.经元素分析、紫外光谱、红外光谱、核磁共振及质谱等分析,证明农抗101-己的结构为β-氨甲酰甲基-γ-(2-羟基-3,5-二甲基苯甲酰)-丁内酯;农抗101-庚的结构为β-[(2-羟基-3,5-二甲基苯甲酰)羟甲基]-戊二酰亚胺.     

ISOLATION, CHEMICAL AND BIOLOGICAL CHARACTERIZATION OF MARGARATENSIN, A NEUROTENSIN-RELATED PEPTIDE FROM THE SKIN OF Rana margaratae

A new neurotensin (NT)-related peptide, margaratensin, was obtained by Sep-Pak C_(18) and RP-HPLC from methanol extracts of the skin of Chinese frog Rana margaratae. The structure of the peptide has been determined to be Asp-Lys-Arg-Pro-Tyr-lle-Leu-His-Glu, which is found to be homologous to the COOH-terminal sequence of NT, but has an extra His-Glu at the COOH-terminus. The synthetic preparation was shown to be indistinguishable from the native peptide during HPLC, amino acid analysis and bioassay. Margaratensin exhibited a hypotensive effect in the rat but the response was weaker than NT. The peptide could induce a potent and reproducible contractile activity on GPI which was different from xenopsin, another NT-related peptide from amphibian skin.     

ISOLATION AND STRUCTURE OF RANAMARGARIN,A NEW TACHYKININ FROM THE SKIN OF CHINESE FROG Rana margaratae

A new tetradecapeptide, ranamargarin, has been isolated by Sep-Pak C_(18) and HPLC from methanol extracts of the skin of the Chinese frogRana margaratae. The sequence of the peptide is: Asp-Asp-Ala-Ser-Asp-Arg-Ala-Lys-Lys-Phe-Tyr-Gly-Leu-Met-NH_2. This structure has been confirmed by synthesis. The peptide is the largest among the amphibian tachykinins and its N-terminal amino acids are quite different from those of the other tachykinins. The formation of the sulfoxide and peak-splitting of ranamargarin during purification procedures are briefly discussed.