Large-scale expression, purification and characterization of small fragments of thrombomodulin: the roles of the sixth domain and of methionine 388.
Large-scale expression, purification and characterization of small fragments of thrombomodulin: the roles of the sixth domain and of methionine 388.
复制标题
血栓调节蛋白小片段的大规模表达、纯化和表征：第六结构域和蛋氨酸 388 的作用。
DOI：
10.1093/protein/8.11.1177
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Komives,EA
中科院分区：
文献类型：
--
作者：
White,CE;Hunter,MJ;Meininger,DP;White,LR;Komives,EA
Fragments of human thrombomodulin (TM) have been expressed in large quantities in the Pichia pastoris yeast expression system and purified to homogeneity. Fermentation of P.pastoris resulted in yields of 170 mg/1 TM. Purification to homogeneity resulted in an overall 10% yield, so that quantities of –20 mg purified fragments can be readily obtained. Smaller fragments of TM, such as the individual fourth or fifth domains, were not active, nor were equimolar mixtures of the two domains. These results demonstrate that the fourth and fifth epidermal growth factor (EGF)–like domains together comprise the smallest active fragment of TM. The fragment containing the fourth and fifth EGFlike domains (TMEGF(4–5)] had 10% the specific activity of rabbit TM. Comparison of the M388L mutant TMEGF(4–5) fragment with the same mutant TMEGF(4–5–6) fragment showed that the fragment with the sixth domain had a 10–fold better Km value for thrombin than the fragment that did not contain the sixth domain; this factor completely accounts for the higher specific activity of the fragments containing the sixth domain. Comparison of the wild–type and M388L mutants showed that the M388L mutation resulted in a 2–fold increase in kcatfor the activation of protein C by the thrombin–TM fragment complex, completely accounting for the 2–fold increase in specific activity of these mutant fragments.
