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Different cation binding to the I domains of α1 and α2 integrins: implication of the binding site structure
Author(s) -
Obšil Tomáš,
Hofbauerová Kateřina,
Amler Evžen,
Teisinger Jan
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)01063-7
Subject(s) - integrin , chemistry , binding site , tryptophan , binding domain , biophysics , protein structure , plasma protein binding , fluorescence , conformational change , stereochemistry , biochemistry , amino acid , biology , receptor , physics , quantum mechanics
In the present work, we studied the interactions of recombinant α1 and α2 integrin I domains with cations Tb 3+ , Mn 2+ , Mg 2+ and Ca 2+ . We observed that α1 and α2 I domains bind these cations with significantly different characteristics. The binding of Mg 2+ by the α1 I domain was accompanied by significant changes of tryptophan fluorescence which could be interpreted as a conformational change. Comparison of the α1 integrin I domain structure obtained by comparative modeling with a known structure of the α2 integrin I domain shows distinct differences in the metal ion binding sites which could explain the differences in cation binding.