Olsen K W
Int J Pept Protein Res. 1983 Oct;22(4):469-75. doi: 10.1111/j.1399-3011.1983.tb02117.x.
The amino acid sequences of two thermophilic and five mesophilic glyceraldehyde-3-phosphate dehydrogenases have been compared with the known three-dimensional structure of this enzyme to determine the factors responsible for thermal stability. The changes are greatest in the S-loop regions at the center of the tetramer, which show a quantitative increase in hydrophobicity and polarity that can strengthen subunit interactions in a complementary manner. The S-loops also show increases in residue volume and bulk that may indicate a tighter packing at the molecular center. In addition, there are changes in the secondary structural parameters indicating that the helices, in particular, may be more stable in the thermophilic proteins. Increases in the hydrophobicity of domain and subunit contacts for the Thermus aquaticus glyceraldehyde-3-phosphate dehydrogenase may explain why it is the most thermostable protein in this series.
已将两种嗜热型和五种中温型甘油醛-3-磷酸脱氢酶的氨基酸序列与该酶已知的三维结构进行比较，以确定决定热稳定性的因素。四聚体中心的S-环区域变化最大，该区域疏水性和极性呈定量增加，可通过互补方式增强亚基间相互作用。S-环的残基体积和大小也有所增加，这可能表明分子中心的堆积更紧密。此外，二级结构参数也有变化，表明特别是螺旋结构在嗜热蛋白中可能更稳定。嗜热水生栖热菌甘油醛-3-磷酸脱氢酶结构域和亚基接触处疏水性的增加，或许可以解释为何它是该系列中最耐热的蛋白质。
