EXAMINATION OF DISSOCIATION OF MULTICHAIN PROTEINS IN GUANIDINE HYDROCHLORIDE BY MEMBRANE OSMOMETRY
EXAMINATION OF DISSOCIATION OF MULTICHAIN PROTEINS IN GUANIDINE HYDROCHLORIDE BY MEMBRANE OSMOMETRY
复制标题
DOI：
10.1021/bi00846a025
复制
发表时间：
1968-01-01
期刊：
影响因子：
2.9
通讯作者：
BARKER, R
中科院分区：
文献类型：
--
作者：
CASTELLINO, FJ;BARKER, R
A number of proteins were examined in dilute aqueous buffers and in concentrated guanidine hydrochloride. Sedimentation coefficients, intrinsic viscosities, and 2nd virial coefficients of these proteins in 6.0 M guanidine hydrochloride-0.5 M mercaptoethanol suggest that all of the proteins are random coils and molecular weight measurements demonstrate that those with sub-units are fully dissociated. Number-average molecular weights, determined by membrane osmometry for the native and guanidine hydrochloride dissociated proteins, are: bovine serum albumin, 68,320 [plus or minus] 600 and 67,790 [plus or minus] 1100; ovalbumin, 44,620 [plus or minus] 300 and 46,530 [plus or minus] 600; horse liver alcohol dehydrogenase (EC 1.1.1.2), 86,000 [plus or minus] 800 and 36,500 [plus or minus] 200; beef heart lactate dehydrogenase (EC 1.1.1.27), 136,290 [plus or minus] 1400 and 36,180 [plus or minus] 800; bovine methemoglobin, 63,720 [plus or minus] 1100 and 15,840 [plus or minus] 800; and rabbit muscle aldolase (EC4.2.16), 156,500 [plus or minus] 1000 and 42,400 [plus or minus] 300. These results indicate that the proteins have 1,1,2,2,4,4, and 4 subunits, respectively. For the native proteins weight-average molecular weights obtained by sedimentation equilibrium centrifugation agree well with those obtained by osmometry. The use of sedimentation equilibrium to determine the weight-average molecular weights of the guanidine hydrochloride dissociated proteins is complicated by the necessity of assuming a value of the partial specific volume, v, for the polypeptide chains in a dissociating medium. However, molecular weights were obtained by this method which were consistent with the results from the membrane osmometry.
