ISSN:
1573-5001
Schlagwort(e):
Protein hydration
;
Residence times of hydration water molecules
;
Hydration of carboxylate groups
;
NMR
;
Nuclear Overhauser effects
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Chemie und Pharmazie
Notizen:
Summary Nuclear Overhauser effects (NOE) were measured between water protons and protons of the glutamic acid side chain of the bicyclic decapeptide $${\text{c - [Arg - Arg - C}}{\text{s - Lys - Gly]}}$$ in aqueous solution. Positive NOEs were observed between the γCH2 group of Glu and the water resonance, with similar NOE intensities at pH 2.0 and pH 6.3 in both the laboratory frame and the rotating frame of reference. These results indicate that the residence times of the hydration water molecules near the side-chain methylene protons are shorter than 500 ps for both the charged form and the uncharged form of Glu, and hence comparable to the water residence times near uncharged amino acid side chains. Furthermore, this study shows that the acidic proton in protonated carboxylic acid groups is not likely to interfere with the observation of polypeptide-hydration water NOEs, which is in contrast to the hydroxyl protons of the side chains of serine, threonine and tyrosine.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00178268
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