Identification of an equilibrium intermediate in the unfolding process of galectin-1, which retains its carbohydrate-binding specificity
✍ Scribed by Marı́a Mercedes Iglesias; Marı́a Teresa Elola; Vanesa Martinez; Nilda Fink; Carlota Wolfenstein-Todel
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 377 KB
- Volume
- 1648
- Category
- Article
- ISSN
- 1570-9639
No coin nor oath required. For personal study only.
✦ Synopsis
The unfolding process of galectin-1 (Gal-1) in the presence of a denaturing agent was examined using fluorescence and far-UV circular dichroism (CD) spectroscopy determinations, and was found to be completely reversible. The data showed that the transitions of guanidine hydrochloride (GdnHCl)-induced lectin unfolding, in the absence of ligand, were biphasic in nature, clearly showing the existence of at least one stable intermediate. On the other hand, the unfolding in the presence of disaccharide yielded data that could fit very well to a two-state model, indicating a stabilizing effect of the ligand. The folding intermediate was further characterized by size exclusion chromatography, near-UV CD and anilinonaphtalene sulfonate binding, and shown to belong to the molten globule type. Strikingly, this intermediate retained its carbohydrate-binding specificity, as evidenced by the tryptophan fluorescence changes detected upon its interaction with lactose.