Showing papers on "NQS published in 1974"

The Effect of the Modification of Amino Groups with β-Naphthoquinone-4-sulfonic Acid on Some Physico-chemical Properties of Myosin

Abstract: In the present work the reaction of myosin with β-naphthoquinone-4-sulfonic acid (NQS) and the effect of modification of myosin with NQS on some physico-chemical properties of myosin were studied. The effects of several bivalent metal ions on ATPase activity of NQS-modified myosin were also investigated. The reactivity of myosin by addition of NQS was at the maximum at pH 9.7.The amount of NQS bound to myosin was greater at lower ionic strengths than at higher ionic strengths.The reduced-viscosity of myosin increased with the increase in the number of amino groups modified with NQS.The solubility of myosin at lower ionic strength (0.2 m KCl) decreased with the increase in the amount of amino groups modified with NQS.The helical content of myosin did not undergo any appreciable change by the NQS-modification of amino groups.The Ca2+-activated ATPase activity of myosin did not undergo any appreciable change by the NQS-modification such that approximately 10 moles of amino group per mole of myosin or less, w...