The electrophoretic analysis of protein extracts from striated rabbit muscle

Publisher Website
Google Scholar
Abstract
Saline extracts of striated rabbit muscle were examined in the Tiselius-Longs-worth electrophoresis apparatus. In the extract obtained with phosphate of pH 7.7 (0.048[image]-Na2HPO4-0.06[image]-Na-H2PO4, [mu] = 0.15) and dialyzed against phosphate buffer containing 0.05[image]-NaCl, total [mu] = 0.15, there are 9 components divisible into the following 3 groups: group I consisting of 3 proteins, n, m and II; group II, 3 proteins, k1, k2 and j; group III, which at pH 7.4 and above contains 2 proteins h and i, and below pH 7.4 is apparently homogeneous; between groups II and III is found a heterogeneous component sp. The mobility curves of the first 8 components have been established at ionic strength [mu][long dash]0.15 over the pH range 5.38-8.04. From these the following isoelectric points have been interpolated: n, 6.75 [plus or minus] 0.05; m, 6.20 [plus or minus] 0.05; 1, 6.00 [plus or minus] 0.05; and k1, 5.50 [plus or minus] 0.05. Some of the constituents show marked variations in solubility over the pH range studied. At an ionic strength [mu] = 0.1, 2 further proteins resolve in group I. When the extracts are dialyzed against distilled water the protein i is apparently completely precipitated. Extraction or dialysis at higher ionic strengths ([mu] = 0.27-0.35) shows that the proteins with higher solubilities in this range migrate close to klj, sp and i. Various aspects of technique apposite to the study of the protein mixtures have been examined experimentally. These include: the effects of thermal convection; the 5 boundary and Svensson effect and their significance in the measurement of relative conc; asymmetries in the ascending and descending mobilities of 3 of the constituents of the mixtures; and the influence of extract conc, potential gradient, and duration of dialysis on the mobility. The relation between the observed electrophoretic components and the classical muscle proteins has been examined.