Levy P L, Pangburn M K, Burstein Y, Ericsson L H, Neurath H, Walsh K A
Proc Natl Acad Sci U S A. 1975 Nov;72(11):4341-5. doi: 10.1073/pnas.72.11.4341.
A comparison of the partial amino-acid sequence of neutral protease A from Bacillus subtilis with the structure of thermolysin (EC 3.4.24.4) from Bacillus thermoproteolyticus reveals that these two proteins are homologous. Of 171 residues placed in neutral protease (54% of the sequence), 83 residues (49%) occur in identical positions in thermolysin, and include nine of the 13 residues previously identified as components of the active site of thermolysin. This similarity provides support for the hypothesis that the two enzymes have similar three-dimensional structures and a common mechanism of action. Since these enzymes differ markedly in their resistance to heat inactivation, a comparison of their structures may eventually provide a chemical basis for explaining the differences in their thermal stability.
将枯草芽孢杆菌中性蛋白酶A的部分氨基酸序列与嗜热解蛋白芽孢杆菌嗜热菌蛋白酶(EC 3.4.24.4)的结构进行比较后发现,这两种蛋白质具有同源性。在中性蛋白酶中的171个残基(占序列的54%)中,有83个残基(49%)在嗜热菌蛋白酶中处于相同位置,其中包括先前确定为嗜热菌蛋白酶活性位点组成部分的13个残基中的9个。这种相似性为这两种酶具有相似的三维结构和共同作用机制这一假说提供了支持。由于这些酶在耐热失活方面存在显著差异,对它们结构的比较最终可能会为解释其热稳定性差异提供化学依据。