FEBS Letters | |
Characterisation of the effects of mutation of the caldesmon sequence 691glu‐trp‐leu‐thr‐lys‐thr696 to pro‐gly‐his‐tyr‐asn‐asn on caldesmon‐calmodulin interaction | |
EL-Mezgueldi, Mohammed2  Marston, Steven B2  Copeland, O'neal2  Huber, Pia A.J2  Levine, Barry A1  | |
[1] School of Biochemistry, University of Birmingham, Birmingham B15 2TT, UK;Imperial College School of Medicine at the National Heart and Lung Institute, Cardiac Medicine, Dovehouse Street, London SW3 6LY, UK | |
关键词: Caldesmon; Calmodulin; Smooth muscle; NMR; Tryptophan fluorescence; Actin; Tropomyosin; Regulation; S-1; chymotryptic myosin subfragment-1; EGTA; ethylene glycol-O; O′-bis(2-aminoethyl)-N; N; N′; N′-tetraacetic acid; DTT; 1; 4-dithio-dl-threitol; PAGE; polyacrylamide gel electrophoresis; SDS; sodium dodecyl sulphate; | |
DOI : 10.1016/S0014-5793(98)00071-4 | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
We have investigated the functional properties of a mutant (Cg1) derived from the C-terminal 99 amino acids of chicken caldesmon, 658–756 (658C) where the sequence 691glu-trp-leu-thr-lys-thr696 is changed to pro-gly-his-tyr-asn-asn. Cg1 bound Ca2+-calmodulin with (1/7)th of the affinity as compared to 658C or whole caldesmon. NMR titrations indicate that the contacts of Ca2+-calmodulin with the Trp-722 region of the peptide are retained but that those at the mutated site are lost. Most importantly Ca2+-calmodulin is not able to reverse the Cg1-induced inhibition. We conclude that the interaction of calmodulin with this caldesmon sequence is crucial for the reversal of caldesmon inhibition of actin-tropomyosin activation of myosin ATPase. The results are interpreted in terms of multi-site attachment of actin and Ca2+-calmodulin to overlapping sequences in caldesmon domain 4b.
【 授权许可】
Unknown
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