Local interactions in bends of proteins.
Local interactions in bends of proteins.
复制标题
蛋白质弯曲中的局部相互作用。
DOI：
--
复制
发表时间：
1977
影响因子：
11.1
通讯作者：
H. Scheraga
中科院分区：
文献类型：
--
作者：
S. Zimmerman;H. Scheraga
计算的概率弯曲形成的47个氨基酸序列的N-乙酰基-N '-甲基酰胺二肽，确定从统计力学分析，使用经验构象能，与观察到的分数的弯曲形成在相同的47个二肽序列中的20个球状蛋白质的X射线结构。之间的协议的计算和观察到的分数的弯曲被发现为26个二肽，这表明，对于那些特定的二肽序列，本地的相互作用占主导地位的远程相互作用，在确定构象偏好。七个二肽序列，其中所有含有一个甘氨酸残基，有一个显着更高的计算比观察到的弯曲的偏好，表明在这些序列的长程和/或溶剂相互作用的强烈影响。14个序列的计算值明显小于观察到的弯曲分数，13个二肽序列含有至少一个极性残基（丝氨酸，天冬酰胺，或天冬氨酸）和/或芳香族残基（苯丙氨酸或酪氨酸），这表明溶剂效应可能发挥重要作用，在这些序列中的构象支配。对20种球状蛋白中二肽序列的分析还表明，4导致1氢键不是稳定蛋白质弯曲的主导因素，并且大多数二肽序列能够形成几种类型的弯曲构象。
Calculated probabilities of bend formation in 47 amino acid sequences of N-acetyl-N'-methylamide dipeptides, determined from a statistical mechanical analysis using empirical conformational energies, were compared with the observed fraction of bends formed in the same 47 dipeptide sequences in the x-ray structures of 20 globular proteins. Agreement between the calculated and observed fraction of bends was found for 26 dipeptides, suggesting that, for those particular dipeptide sequences, local interactions dominate over long-range interactions in determining conformational preference. Seven dipeptide sequences, all of which contained a Gly residue, had a significantly higher calculated than observed bend preference, indicating the strong influence of long-range and/or solvent interactions in those sequences. Of the 14 sequences for which the calculated was significantly less than the observed bend fraction, 13 dipeptide sequences contained at least one polar residue (Ser, Asn, or Asp) and/or an aromatic residue (Phe or Tyr), suggesting that solvent effects may play an important role in dictating the conformation in these sequences. The analysis of dipeptide sequences in the twenty globular proteins also indicated that the 4 leads to 1 hydrogen bond is not a dominant factor in stabilizing bends in proteins, and that most dipeptide sequences are capable of forming several types of bend conformations.