Interaction of 75–106 actin peptide with myosin subfragment-1 and its trypsin modified derivative

• Published in: Biochimica et biophysica acta Vol. 1427; no. 1; pp. 105 - 111
• Main Authors: Labbé, Jean-Pierre, Chamayou, Sandrine, Benyamin, Yves
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 14.03.1999
• Subjects: Actin peptide; Actins - chemistry; Adenosine Triphosphatases - chemistry; Amino Acid Sequence; ATPase; Binding Sites; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Fluorescence Polarization; Molecular Sequence Data; Myosin subfragment-1; Myosin Subfragments - chemistry; Peptide Fragments - chemistry; Protein Structure, Secondary; Trypsin; Actin peptide; ATPase; Myosin subfragment-1
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(99)00011-2

To explore the role of a hydrophobic domain of actin in the interaction with a myosin chain we have synthesized a peptide corresponding to residues 75–106 of native actin monomer and studied by fluorescence and ELISA the interaction (13±2.6×10 −6 M) with both S-1 and (27 kDa–50 kDa–20 kDa) S-1 trypsin derivative of myosin. The loop corresponding to 96–103 actin residues binds to the S-1 only in the absence of Mg-ATP and under similar conditions but not to the trypsin derivative S-1. Biotinylated C74-K95 and I85-K95 peptide fragments were purified after actin proteolysis with trypsin. The C74-K95 peptide interacted with both S-1 and the S-1 trypsin derivative with an apparent K d(app) of 6±1.2×10 −6 M in the presence or absence of nucleotides. Although peptide fragment I85-K95 binds to S-1 with a K d(app) of 12±2.4×10 −6 M, this fragment did not bind to the trypsin S-1 derivative. We concluded that the actin 85–95 sequence should be a potential binding site to S-1 depending of the conformational state of the intact 70 kDa segment of S-1.