Characterization of S-100b binding epitopes. Identification of a novel target, the actin capping protein, CapZ
| Autor: | Gordon A. Jamieson, Vasily V. Ivanenkov, Ruth V.W. Dimlich, Eric Gruenstein |
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| Rok vydání: | 1995 |
| Předmět: |
Molecular Sequence Data
Muscle Proteins Peptide Fluorescence Polarization S100 Calcium Binding Protein beta Subunit Biochemistry Epitopes Tumor Cells Cultured Animals Actin-binding protein Amino Acid Sequence Nerve Growth Factors Molecular Biology Peptide sequence Actin chemistry.chemical_classification CapZ Actin Capping Protein biology Binding protein Calcium-Binding Proteins Microfilament Proteins S100 Proteins CapZ Cell Biology Amino acid Rats Cross-Linking Reagents chemistry biology.protein Cattle Neuroglia Oligopeptides |
| Zdroj: | The Journal of biological chemistry. 270(24) |
| ISSN: | 0021-9258 |
| Popis: | Short amino acid sequences that interact with the Ca2+ binding protein S-100b were identified by screening a bacteriophage random peptide display library. S-100b binding bacteriophages were selected by Ca(2+)-dependent affinity chromatography, and the sequence of the random peptide insert contained in 51 clones was determined. Alignment of the sequence of 44 unique S-100b binding peptides identified a common motif of eight amino acids. A subgroup of peptides that contained sequences with the highest degree of similarity had the consensus motif (K/R)(L/I)XWXXIL, in which predominantly P, S, and N were found in position 3, and S and D were found in position 5. Analysis of sequence databanks identified a similar sequence in the COOH-terminal region of the alpha-subunit of actin capping proteins. The peptide TRTKIDWNKILS (TRTK-12), corresponding to the region of greatest homology within this region of the subunit of actin capping proteins (e.g. amino acids 265-276 in CapZ alpha 1 and CapZ alpha 2), was synthesized and shown by fluorescence spectrophotometry to bind S-100b in a Ca(2+)-dependent manner. Gel overlay and cross-linking experiments demonstrated the interaction of S-100b with CapZ to be Ca2+ dependent. Moreover, this interaction was blocked by addition of TRTK-12 peptide. These results identify Ca(2+)-dependent S-100b target sequence epitopes and designate the carboxyl terminus of the alpha-subunit of actin capping proteins, like CapZ, to be a target of S-100b activity. The high level of conservation within this region of actin capping proteins and the apparent high affinity of this interaction strongly suggest that the interaction between S-100b and the alpha-subunit of actin capping proteins is biologically significant. |
| Databáze: | OpenAIRE |
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