Cooperative influence of water binding to peptides by NH···OH 2 and CO···HOH hydrogen bonds: Study by Ab Initio calculations

• Published in: International journal of quantum chemistry 2012-05, Vol.112 (10), p.2336-2341
• Main Authors: Sun, Chang‐Liang, Wang, Chang‐Sheng
• Format: Article
• Language: English
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/qua.23215

In this article, the geometry structures of hydrogen bond chains of formamide and N‐ methylacetamide and their hydrogen‐bonded complexes with water were optimized at the MP2/6‐31G* level. Then, we performed Møller–Plesset perturbation method with 6‐311++g**, aug‐cc‐pvtz basis sets to study the cooperative influence to the total hydrogen bond energy by the NH ··· OH 2 and CO ··· HOH hydrogen bonds. On the basis of our results, we found that the cooperativity of the hydrogen‐bonded complexes become weaker as NH ··· OH 2 and CO ··· HOH hydrogen bonds replacing NH ··· OC hydrogen bonds in protein and peptide. It means that the NH and CO bonds in peptide prefer to form NH ··· OC hydrogen bond rather than to form CO ··· HOH and NH ··· OH 2 . It is significant for understanding the structures and properties of the helical or sheet structures of protein and peptide in biological systems. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011