Full-contact domain labeling: identification of a novel phosphoinositide binding site on gelsolin that requires the complete protein
| Autor: | Li Feng, Helen L. Yin, Jian Chen, Glenn D. Prestwich, Marisan Mejillano |
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| Rok vydání: | 2001 |
| Předmět: |
Models
Molecular Phosphatidylinositol 4 5-Diphosphate Molecular model Polymers Molecular Sequence Data Peptide macromolecular substances Photoaffinity Labels Biochemistry Peptide Mapping chemistry.chemical_compound Structure-Activity Relationship Moiety Animals Humans Inositol Phosphatidylinositol Amino Acid Sequence Horses Binding site Phosphorylation Actin Gelsolin chemistry.chemical_classification Binding Sites Actins Peptide Fragments Protein Structure Tertiary chemistry Calcium Dimerization |
| Zdroj: | Biochemistry. 40(4) |
| ISSN: | 0006-2960 |
| Popis: | Gelsolin, an actin and phosphoinositide binding protein, was photoaffinity labeled using a variety of benzophenone-containing phosphoinositide polyphosphate analogues. The N-terminal half and the C-terminal half of gelsolin showed synergy in the binding of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2]. Competitive displacement experiments with dibutyryl, dioctanoyl, or dipalmitoyl derivatives of PtdIns(4,5)P(2) suggested that, in addition to the inositol headgroup, a diacylglyceryl moiety was important for binding; these analogues also inhibited the gelsolin-severing activity of F-actin. In addition to the previously identified PtdIns(4,5)P2 binding site in the N-terminal half of gelsolin, a new binding site was identified in the C-terminal half by mapping the photocovalently modified peptide fragments. Moreover, increasing concentrations of Ca(2+) decreased the binding of the photolabile analogues to the C-terminal phosphoinositide binding site on gelsolin. A molecular model of the binding of PtdIns(4,5)P2 within two folded repeats of gelsolin has been calculated using these data. |
| Databáze: | OpenAIRE |
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