Interaction between stretch of residues 633-642 (actin binding site) and nucleotide binding site on skeletal myosin subfragment 1 heavy chain

Biochemistry ◽  
1989 ◽  
Vol 28 (23) ◽  
pp. 9123-9128 ◽  
Author(s):  
Patrick Chaussepied
Keyword(s):  
Binding Site ◽  
Heavy Chain ◽  
Nucleotide Binding ◽  
Nucleotide Binding Site ◽  
Actin Binding ◽  
Myosin Subfragment ◽  
Skeletal Myosin ◽  
Myosin Subfragment 1 ◽  
Actin Binding Site

scholarly journals Plasma membrane association of Acanthamoeba myosin I.

1989 ◽  
Vol 109 (4) ◽  
pp. 1519-1528 ◽  
Author(s):  
H Miyata ◽  
B Bowers ◽  
E D Korn
Keyword(s):  
Plasma Membrane ◽  
Binding Site ◽  
Heavy Chain ◽  
Membrane Fraction ◽  
Plasma Membranes ◽  
Actin Binding ◽  
Plasma Membrane Fraction ◽  
Myosin I ◽  
Membrane Bound ◽  
Actin Binding Site

Myosin I accounted for approximately 2% of the protein of highly purified plasma membranes, which represents about a tenfold enrichment over its concentration in the total cell homogenate. This localization is consistent with immunofluorescence analysis of cells that shows myosin I at or near the plasma membrane as well as diffusely distributed in the cytoplasm with no apparent association with cytoplasmic organelles or vesicles identifiable at the level of light microscopy. Myosin II was not detected in the purified plasma membrane fraction. Although actin was present in about a tenfold molar excess relative to myosin I, several lines of evidence suggest that the principal linkage of myosin I with the plasma membrane is not through F-actin: (a) KI extracted much more actin than myosin I from the plasma membrane fraction; (b) higher ionic strength was required to solubilize the membrane-bound myosin I than to dissociate a complex of purified myosin I and F-actin; and (c) added purified myosin I bound to KI-extracted plasma membranes in a saturable manner with maximum binding four- to fivefold greater than the actin content and with much greater affinity than for pure F-actin (apparent KD of 30-50 nM vs. 10-40 microM in 0.1 M KCl plus 2 mM MgATP). Thus, neither the MgATP-sensitive actin-binding site in the NH2-terminal end of the myosin I heavy chain nor the MgATP-insensitive actin-binding site in the COOH-terminal end of the heavy chain appeared to be the principal mechanism of binding of myosin I to plasma membranes through F-actin. Furthermore, the MgATP-sensitive actin-binding site of membrane-bound myosin I was still available to bind added F-actin. However, the MgATP-insensitive actin-binding site appeared to be unable to bind added F-actin, suggesting that the membrane-binding site is near enough to this site to block sterically its interaction with actin.

Crosslinking of the skeletal myosin subfragment-1 heavy chain to the N-terminal actin segment of residues 40-113

Biochemistry ◽  
1988 ◽  
Vol 27 (15) ◽  
pp. 5728-5736 ◽  
Author(s):  
Raoul Bertrand ◽  
Patrick Chaussepied ◽  
Ridha Kassab ◽  
Mireille Boyer ◽  
Claude Roustan ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Myosin Subfragment ◽  
Skeletal Myosin ◽  
Myosin Subfragment 1
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