ISSN:
1432-1017
Schlagwort(e):
Raman spectroscopy
;
α-lactalbumin
;
tyrosine
;
protein conformation
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Physik
Notizen:
Abstract Side group behaviour is often used for conformational studies of proteins. We have performed Raman spectroscopic measurements on the tyrosine groups of bovine α-lactalbumin. The 850/830 cm-1 doublet intensity ratio is a direct measure of the negative charge state of the phenolic oxygen and of the tyrosine environment. pH measurements confirm the existence of an acid conformer of BLA, that is comparable to, but clearly distinguishable from the apo-conformer. Following the Siamwiza theory, the Tyr groups in this partially unfolded state are situated in a more hydrophobic environment. Observation of Tyr groups behaviour in the denaturated states obtained by thermal or chemical treatment leads us to the same conclusion. However, the behavior of tryptophan groups is quite different. In an unfolded sate, the Trp residues are mostly exposed to the solvent. The stabilizing role of Ca2+ and Na+ ions in BLA is also investigated.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00254864
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