Title
Stability of the hydration layer of tropocollagen: A QM study.
Abstract
Collagen is a triple helical protein, highly hydrated in nature. Bella and Berman (J Mol Biol 1996, 264, 734) have reported the structure of the first hydration layer. Water molecules form bridges of different length around the POG repeats and self assemble into left-handed helical water threads. To explore the stability of these specifically hydrated places, we have designed suitable QM models: each comprises a triple helix formed by 18 residues surrounded by 8 to 12 explicit waters. Two sets of amino acids were used, one standing for the core structural subunit of tropocollagen (POG-model) and one for its natural enzyme recognition sites (AAG-model). We have determined the stability order of the water binding places, the strongest being -8.1 kcal mol(-1), while the weakest -6.1 kcal mol(-1) per hydrogen bond. In X-ray structures, each triplet of tropocollagen is shielded by six to nine water molecules. Beside the mandatory six, the "surplus" three water molecules further strengthen the binding of all the others. However, the displacement of selected water molecules turns out to be energy neutral. These water binding places on the surface of the triple helix can provide explanation on how an almost liquid-like hydration environment exists between the closely packed tropocollagens (Henkelman et al, Magn Reson Med 1994, 32, 592). It seems that these water reservoirs or buffers can provide space for "hole conduction" of water molecules and thus contribute to the elasticity of collagen. (C) 2009 Wiley Periodicals, Inc. J Comput Chem 31: 764-777, 2010
Year
DOI
Venue
2010
10.1002/jcc.21361
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
Field
DocType
collagen,hydration,quantumchemical calculation
Crystallography,Molecule,Computational chemistry,Chemistry,Triple helix,Tropocollagen,Hydrogen bond,Elasticity (economics)
Journal
Volume
Issue
ISSN
31
4
0192-8651
Citations 
PageRank 
References 
0
0.34
2
Authors
2
Name
Order
Citations
PageRank
Villö K. Pálfi110.82
András Perczel23916.63