scholarly journals Interaction of skeletal-muscle myosin subfragment-1 with the actin-(338-348) peptide.

1994 ◽  
Vol 299 (3) ◽  
pp. 875-879 ◽  
Author(s):  
J P Labbé ◽  
S Lelievre ◽  
M Boyer ◽  
Y Benyamin

The data presented here confirm and provide further experimental evidence that rabbit skeletal-muscle myosin subfragment-1 (S-1) binds to the postulated actin-(338-348) hydrophobic segment [Kabsch, Mannherz, Suck, Pai and Holmes (1990) Nature (London) 347, 37-44] with high affinity in the absence and presence of MgATP. The apparent dissociation constant of the S-1 interaction (5.5 x 10(-7) M) with the actin-(338-348) peptide was of the same order of magnitude as that of the actin-(18-28) binding site (2 x 10(-6) M). In similar conditions, fragmented (27 kDa-50 kDa-20 kDa) S-1 also bound to the peptide. Antibodies directed to the vicinal sequence 348-358 were rapidly eliminated from actin by S-1 interaction and weakened S-1 binding to monomeric or filamentous actin. The antigenic site (348-358) is located very close to the C-terminal S-1-binding site (360-369) and encompasses some residues (Leu-349 and Phe-352) included in the hydrophobic S-1-binding region [Schröder, Manstein, Jahn, Holden, Rayment, Holmes and Spudich (1993) Nature (London) 364, 171-174]. It was observed that anti-[actin-(348-358)] antibodies were also unable to decrease actomyosin ATPase activity, in contrast with previous results obtained with anti-[actin-(18-28)] antibodies [Adams and Reisler (1993) Biochemistry 32, 5051-5056]. The hydrophobic actin-(338-348) peptide used in considerable excess was unable to perturb acto-S-1 and S-1 activities in contrast with results obtained with the N-terminal actin peptide [Kôgler, Moir, Trayer and Ruegg (1991) FEBS Lett. 294, 31-34].

1997 ◽  
Vol 65 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Karen Claire ◽  
Robert Pecora ◽  
Stefan Highsmith

1990 ◽  
Vol 271 (2) ◽  
pp. 407-413 ◽  
Author(s):  
J P Labbé ◽  
C Méjean ◽  
Y Benyamin ◽  
C Roustan

Evidence for the participation of the 1-7 and 18-28 N-terminal sequences of actin at different steps of actin-myosin interaction process is well documented in the literature. Cross-linking of the rigor complex between filamentous actin and skeletal-muscle myosin subfragment 1 was accomplished by the carboxy-group-directed zero-length protein cross-linker, 1-ethyl-3-[3-(dimethylamino)propyl]carbodi-imide. After chaotropic depolymerization and thrombin digestion, which cleaves only actin, the covalent complex with Mr 100,000 was characterized by PAGE. The linkage was identified as being between myosin subfragment 1 (S-1) heavy chain and actin-(1-28)-peptide. The purified complex retained in toto its ability to combine reversibly with fresh filamentous actin, but showed a decrease in the Vmax. of actin-dependent Mg2(+)-ATPase. By using e.l.i.s.a., S-1 was observed to bind to coated monomeric actin or its 1-226 N-terminal peptide. This interaction strongly interfered with the binding of antibodies directed against the 95-113 actin sequence. Moreover, S-1 was able to bind with coated purified actin-(40-113)-peptide. Finally, antibodies directed against the 18-28 and 95-113 actin sequence, which strongly interfered with S1 binding, were unable to compete with each other. These results suggest that two topologically independent regions are involved in the actin-myosin interface: one located in the conserved 18-28 sequence and the other near residues 95-113, including the variable residue at position 89. Other experiments support the ‘multisite interface model’, where the two actin sites could modulate each other during S-1 interaction.


Biochemistry ◽  
1996 ◽  
Vol 35 (7) ◽  
pp. 2299-2308 ◽  
Author(s):  
Paul B. Conibear ◽  
Daren S. Jeffreys ◽  
Charnjit K. Seehra ◽  
Robert J. Eaton ◽  
Clive R. Bagshaw

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