Interaction of the N-terminal part of the A1 essential light chain with the myosin heavy chain.
The kinetics of actin-dependent MgATPase activity of skeletal muscle myosin subfragment 1 (S1) isoform containing the A1 essential light chain differ from those of the S1 isoform containing the A2 essential light chain. The differences are due to the presence of the extra N-terminal peptide comprising 42 amino acid residues in the A1 light chain. This peptide can interact with actin; heretofore, there have no been reports of the direct interaction between this peptide and the heavy chain of S1. Here, using the zero-length cross-linker 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and S. aureus V8 protease, we show for the first time that the N-terminal part of the A1-light chain can interact with the 22-kDa fragment of the S1 heavy chain. No such interaction has been observed for the S1(A2) isoenzyme. Localization of residues which can possibly react with the cross-linker suggests that the interaction might involve the N-terminal residues of the A1 light chain and the converter region of the heavy chain.
Department of Muscle Biochemistry, Nencki Institute of Experimental Biology, 3 Pasteur Street, Warsaw, PL-02-093, Poland. basiap@nencki.gov.pl
B
B
Pliszka
M J
MJ
Redowicz
D
D
Stepkowski
D000199:Actins / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000737:chemistry; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000737:chemistry; D018995:Myosin Heavy Chains / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D015879:Myosin Subfragments / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits; D012697:Serine Endopeptidases / Q000378:metabolism
D000199:Actins; D003432:Cross-Linking Reagents; D015879:Myosin Subfragments; D000255:Adenosine Triphosphate; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D018995:Myosin Heavy Chains; D005022:Ethyldimethylaminopropyl Carbodiimide