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Do all backbone polar groups in proteins form hydrogen bonds?
Author(s) -
Fleming Patrick J.,
Rose George D.
Publication year - 2005
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.051454805
Subject(s) - hydrogen bond , chemistry , peptide , low barrier hydrogen bond , peptide bond , hydrogen , molecule , polar , crystallography , biochemistry , organic chemistry , physics , astronomy
Evidence from proteins and peptides supports the conclusion that intrapeptide hydrogen bonds stabilize the folded form of proteins. Paradoxically, evidence from small molecules supports the opposite conclusion, that intrapeptide hydrogen bonds are less favorable than peptide–water hydrogen bonds. A related issue—often lost in this debate about comparing peptide–peptide to peptide– water hydrogen bonds—involves the energetic cost of an unsatisfied hydrogen bond. Here, experiment and theory agree that breaking a hydrogen bond costs between 5 and 6 kcal/mol. Accordingly, the likelihood of finding an unsatisfied hydrogen bond in a protein is insignificant. This realization establishes a powerful rule for evaluating protein conformations.