Hohn T M, Paznokas J L
J Bacteriol. 1987 Aug;169(8):3525-30. doi: 10.1128/jb.169.8.3525-3530.1987.
The dimorphic phycomycete Mucor racemosus was found to contain up to five electrophoretic forms of pyruvate kinase (ATP: pyruvate 2-O-phosphotransferase, EC 2.7.1.40) depending on growth conditions. M. racemosus hyphal cells grown on glutamic acid as the carbon source contained only the fastest electrophoretic form, designated PK1, while yeast cells grown on glucose contained only the slowest electrophoretic form, PK5. Intermediate electrophoretic forms PK2, PK3, and PK4 as well as PK1 and PK5 were found in hyphal cells grown on media containing fructose or cellibiose. All five electrophoretic forms had molecular weights of ca. 230,000 as determined from plots of log Rm versus acrylamide gel concentration. Both PK1 and PK5 were purified to homogeneity and determined to be homotetramers, with subunit molecular weights of 54,000 and 58,100, respectively. The amino acid content of PK1 and PK5 was determined and found to be similar but not identical. Analysis of limited tryptic digests and cyanogen bromide cleavage fragments of PK1 and PK5 indicate that the subunits of the two isozymes are significantly different.
已发现二态藻状菌总状毛霉根据生长条件含有多达五种丙酮酸激酶（ATP：丙酮酸2 - O - 磷酸转移酶，EC 2.7.1.40）的电泳形式。以谷氨酸作为碳源生长的总状毛霉菌丝细胞仅含有最快的电泳形式，命名为PK1，而以葡萄糖生长的酵母细胞仅含有最慢的电泳形式，PK5。在以果糖或纤维二糖为培养基生长的菌丝细胞中发现了中间电泳形式PK2、PK3和PK4以及PK1和PK5。根据log Rm对丙烯酰胺凝胶浓度的作图测定，所有五种电泳形式的分子量约为230,000。PK1和PK5均被纯化至同质，并确定为同四聚体，亚基分子量分别为54,000和58,100。测定了PK1和PK5的氨基酸含量，发现它们相似但不相同。对PK1和PK5的有限胰蛋白酶消化物和溴化氰裂解片段的分析表明，这两种同工酶的亚基有显著差异。
