|
ИСТИНА |
Войти в систему Регистрация |
ИПМех РАН |
||
Point amino acid substitutions at Ca2+-binding sites of recoverin. I. The mechanism of successive filling of the Ca2+-binding sitesстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Permyakov S.E., Senin I.I., Uverskii V.N., Cherskaya A.M., Shulga-Morskoy S.V., Zinchenko D.V., Alekseev A.M., Zargarov A.A., Lipkin V.M., Philippov P.P., Permyakov E.A.
- Журнал: Bioorganicheskaya Khimiya
- Том: 25
- Номер: 10
- Год издания: 1999
- Издательство: Izdatel'stva Nauka
- Местоположение издательства: Russian Federation
- Первая страница: 742
- Последняя страница: 746
- Аннотация: The molecule of photoreceptor Ca2+-binding protein recoverin contains four potential Ca2+-binding sites of the EF-hand type, but only two of them (the second and the third) can actually bind calcium ions. We studied the interaction of Ca2+ with recoverin and its mutant forms containing point amino acid substitutions at the working Ca2+-binding sites by measuring the intrinsic protein fluorescence and found that the substitution of Gln for Glu residues chelating Ca2+ in one (the second or the third) or simultaneously in bath (the second and the third) Ca2+-binding sites changes the affinity of the protein to Ca2+ ions in different ways. The Gln for Glu121 substitution in the third site and the simultaneous Gln substitutions in the second (for Glu85) and in the third (for Glu121) sites result in the complete loss of the capability of recoverin for a strong binding of Ca2+-ions. On the other hand, the Gln for Glu85 substitution only in the second site moderately affects its affinity to the cation. Hence, we assumed that recoverin successively binds Ca2+-ions: the second site is filled with the cation only after the third site has been filed. The binding constants for the third and the second Ca2+-binding sites of recoverin determined by spectrofluorimetric titration are 3.7 x 10(6) and 3.1 x 10(5) M-1, respectively.
- Добавил в систему: Филиппов Павел Павлович