ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The crystal structure of N-acetyl-L-4-hydroxyproline (Hyp) was determined by direct methods. (The crystal is orthorhombic with the space group P212121.) The acetyl group is in the trans conformation and the pyrrolidine ring puckers at Cγ (CsCγ envelope), as in most Hyp residues. According to the rotation angle ψ = -30°, the N-acetyl-L-4Hyp has the same conformation as an α-helix of prolyl residues. The crystal packing is stabilized by hydrogen bonds between three different molecules and the same molecule of water. One of the water bridges involves the carbonyl of the N-acetyl group of one molecule and the hydrogen atom of the 4-OH group of another. Such an arrangement has been proposed to explain the high stability of (Gly-L-Pro-L-4Hyp)n. A second bridge involves the two hydrogens of the water molecule and the carbonyl groups of two neighbouring molecules, as already proposed in a dihydrated model of collagen. These experimental features, which are discussed in relation to the different models of collagen, allow us to propose an hypothetical arrangement for the water molecule which is strongly retained in the triple helix of (Gly-L-Pro-L-4Hyp)n.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1979.360180509
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