Shul'mina A I, Cherniak V Ia, Magretova N N, Malova E L, Dronova L A
Biokhimiia. 1976;41(7):1229-34.
Serine proteases inhibitor with pl-7.3, isolated from potatoe tubers by isoelectric focusing procedure as described previously (V.V. Mosolov et al., Bioorganic Chem., 1, 1449, 1975), was homogeneous under ultracentrifugation, having sedimentation coefficient S20,w 2.8S. Its molecular weight, investigated by sedimentation equilibrium and gel filtration through Sephadex G-100, was found to be 32500 and 31500 respectively. The Stokes radius R and frictional ratio f/fo were found to be 24 A and 1.14. The molecular weight of the inhibitor as determined by sodium dodecylsulfate polyacrylamide electrophoresis was twice as low as determined in ultracentrifuge and by gel filtration procedure. It is suggested that the inhibitor is dimer and consists of two protomers of equal molecular weight.
通过如先前所述的等电聚焦程序（V.V. 莫索洛夫等人，《生物有机化学》，1，1449，1975）从马铃薯块茎中分离出的丝氨酸蛋白酶抑制剂，其等电点为7.3，在超速离心下呈均一状态，沉降系数S20,w为2.8S。通过沉降平衡和经葡聚糖G - 100的凝胶过滤法研究其分子量，分别为32500和31500。斯托克斯半径R和摩擦比f/fo分别为24 Å和1.14。通过十二烷基硫酸钠聚丙烯酰胺电泳测定的抑制剂分子量比在超速离心机和凝胶过滤法中测定的低两倍。推测该抑制剂为二聚体，由两个分子量相等的原体组成。
