Role of the C-terminal extremities of the smooth muscle myosin heavy chains: implication for assembly properties.
The two light meromyosin isoforms from rabbit smooth muscle were prepared as recombinant proteins in Escherichia coli. These species which differed only by their C-terminal extremity showed the same circular dichroism spectra and endotherms in measurements of differential scanning calorimetry. Their solubility properties were different at pH 7.0 in the absence of monovalent salts. Their paracrystals formed at low pH differed by their aspect and number. These data suggest a role for the C-terminal extremity of myosin heavy chains in the assembly of myosin molecules in filaments and consequently in the contractility of smooth muscles.
Quevillon-Chéruel
S
S
Laboratoire des Gènes et Protéines Musculaires, CNRS EP 1088, Université de Paris-Sud, Orsay, France.
Foucault
G
G
Desmadril
M
M
Lompré
A M
AM
Béchet
J J
JJ
D000818:Animals; D001483:Base Sequence; D004926:Escherichia coli; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000737:chemistry / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D011487:Protein Conformation; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D011994:Recombinant Proteins; D018995:Myosin Heavy Chains