Indication for an allosteric effect of ADP on actomyosin gels and glycerinated fibres from insect fibrillar flight muscle

Abstract

Adenosinetriphosphatase activity of actomyosin and myosin isolated from insect flight muscles have been extensively studied by Maruyama (1958).The requirement of ATP for tension and oscillatory work in glycerinated fibres has recently been demonstrated by Jewell, Pringle and Ru¨egg (1964). The present paper describes a regulation of actomyosin interactions by ADP, as manifested by a co-operative inhibition of the Ca ++-activated ATPase and increased tension developed by glycerinated fibres in the presence of this nucleotide. A structural transition has also been observed in actomyosin gels in the presence of ADP.