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Effect of intramolecular cross-linking between glutamine-41 and lysine-50 on actin structure and function.
- Source :
-
Journal of muscle research and cell motility [J Muscle Res Cell Motil] 2000; Vol. 21 (5), pp. 405-14. - Publication Year :
- 2000
-
Abstract
- Subdomain 2 of actin is a dynamic segment of the molecule. The cross-linking of Gln-41 on subdomain 2 to Cys-374 on an adjacent monomer in F-actin inhibits actomyosin motility and force generation (Kim et al., 1998; Biochemistry 37, 17,801-17,809). To shed light on this effect, additional modifications of the Gln-41 site on actin were carried out. Both intact G-actin and G-actin cleaved by subtilisin between Met-47 and Gly-48 in the DNase 1 binding loop of subdomain 2 were treated with bacterial transglutaminase. According to the results of Edman degradation, transglutaminase introduced an intramolecular zero-length cross-linking between Gln-41 and Lys-50 in both intact and subtilisin cleaved actins. This cross-linking perturbs G-actin structure as shown by the inhibition of subtilisin and tryptic cleavage in subdomain 2, an allosteric inhibition of tryptic cleavage at the C-terminus and decrease of modification rate of Cys-374. The cross-linking increases while the subtilisin cleavage dramatically decreases the thermostability of F-actin. The Mg- and S1-induced polymerizations of both intact and subtilisin cleaved actins were only slightly influenced by the cross-linking. The activation of S1 ATPase by actin and the sliding speeds of actin filaments in the in vitro motility assays were essentially unchanged by the cross-linking. Thus, although intramolecular cross-linking between Gln-41 and Lys-50 perturbs the structure of the actin monomer, it has only a small effect on actin polymerization and its interaction with myosin. These results suggest that the new cross-linking does not alter the intermonomer interface in F-actin and that changes in actomyosin motility reported for the Gln-41-Cys-374 intrastrand cross-linked actin are not due to decreased flexibility of loop 38-52 but to constrains introduced into the F-actin structure and/or to perturbations at the actin's C-terminus.
- Subjects :
- Actins chemistry
Actins drug effects
Adenosine Triphosphate metabolism
Animals
Binding Sites drug effects
Binding Sites physiology
Cell Movement drug effects
Cell Movement physiology
Deoxyribonuclease I chemistry
Deoxyribonuclease I drug effects
Deoxyribonuclease I metabolism
Glutamine chemistry
Lysine chemistry
Muscle Contraction drug effects
Muscle Contraction physiology
Myosins chemistry
Myosins drug effects
Myosins metabolism
Polymers metabolism
Protein Structure, Tertiary physiology
Rabbits
Subtilisins drug effects
Subtilisins metabolism
Transglutaminases pharmacology
Actins metabolism
Cross-Linking Reagents metabolism
Glutamine metabolism
Lysine metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0142-4319
- Volume :
- 21
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Journal of muscle research and cell motility
- Publication Type :
- Academic Journal
- Accession number :
- 11129431
- Full Text :
- https://doi.org/10.1023/a:1005649604515