去B链羧端七肽胰岛素的制备及结晶

以去B链羧端五肽胰岛素为原料,用羧肽酶-A限制性酶解,制得了去B链羧端七肽胰岛素(DHPI).产物经Sephadex G-50纯化,并经羧端、羧端肽、氨基酸组成分析以及聚丙烯酰胺凝胶板电泳分析.证明得到了纯的DHPI.DHPI在0.05 M柠檬酸缓冲液(pH5.9—6.1,含33％丙酮及少量醋酸锌)中可以结晶,结晶是片状的.用凝胶电泳进一步纯化的DHPI经小白鼠惊厥法测定是没有活力的.     

去七肽胰岛素(B24-30)晶体结构研究——单晶培养及晶体学参数测定

本文利用静止法在柠檬酸缓冲液中培养出可供X-射线结构分析用的去B链羧端七肽(B24—30)胰岛素单晶。晶体衍射分辨率不小于2埃。晶体学参数测定结果为正交晶系,空间群P2_12_12_1,每个结晶学不对称单位含两个去七肽胰岛素分子。     

CRYSTALLOGRAPHIC STUDIES ON DESHEPTAPEPTIDE (B24-30) INSULIN——GROWTH OF SINGLE CRYSTAL AND DETERMINATION OF ITS CRYSTALLOGRAPHIC PARAMETERS

Satisfactory single crystals of desheptapeptide (B24----30) insulin for X-ray crystal struc-ture analysis have been grown in citrate buffer by still-setting method. The diffraction ofthe crystal extends to 2 A spacing. Its crystal system is orthorhombic space group P2_12_12_1.Each crystallographic asymmetric unit contains two molecules of desheptapeptide insulin.