Titani K, Koide A, Hermann J, Ericsson L H, Kumar S, Wade R D, Walsh K A, Neurath H, Fischer E H
Proc Natl Acad Sci U S A. 1977 Nov;74(11):4762-6. doi: 10.1073/pnas.74.11.4762.
The sequence of the 841 amino acid residues in each subunit (molecular weight 97,412) of rabbit muscle glycogen phosphorylase b (1,4-alpha-D-glucan:orthophosphate alpha-glucosyltransferase; EC 2.4.1.1) has been determined. The general strategy was based on limited proteolysis of native phosphorylase b by subtilisin BPN', yielding two large segments (light and heavy) which were fragmented by cleavage at methyonyl-, asparaginyl-glycine, and aspartyl-proline bonds. Analysis of two cyanogen bromide fragments (CB14 and CB17) isolated from the intact molecule yielded the overlap between the light and heavy fragments and the remainder of the sequence. The residues involved in the covalent and allosteric control of the enzyme, and in the binding of the cofactor pyridoxal 5'-phosphate, were identified as serine-14, tyrosine-155, and lysine-679, respectively.
已确定兔肌肉糖原磷酸化酶b(1,4-α-D-葡聚糖:正磷酸α-葡糖基转移酶;EC 2.4.1.1)每个亚基(分子量97,412)中841个氨基酸残基的序列。总体策略是基于枯草杆菌蛋白酶BPN'对天然磷酸化酶b的有限蛋白水解,产生两个大片段(轻链和重链),它们通过甲硫氨酰、天冬氨酰-甘氨酸和天冬氨酰-脯氨酸键的裂解而碎片化。对从完整分子中分离出的两个溴化氰片段(CB14和CB17)的分析得出了轻链和重链片段之间的重叠以及序列的其余部分。分别确定了参与酶的共价和变构控制以及辅因子磷酸吡哆醛5'-磷酸结合的残基为丝氨酸-14、酪氨酸-155和赖氨酸-679。