A study of the dynamic properties of actomyosin systems by quasi-elastic light scattering.
A laser light source and a digital autocorrelator were employed in the study of the molecular dyanmics of acto-heavy meromyosin during the splitting of ATP. Low protein concentrations were used, so that molecular and not gel properties were evident. The addition of Mg2+ to acto-heavy meromyosin solutions in the presence of ATP caused a marked widening of the spectrum at high scattering angles. No such change was observed when chemically inactivated heavy meromyosin was used when actin was cross-linked or when the proteins were in a high ionic strength solution. The data can be interpreted in terms of pronounced change in flexibility of acto-heavy meromyosin induced by active mechanochemical coupling.
D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D007834:Lasers; D008274:Magnesium / Q000494:pharmacology; D015879:Myosin Subfragments / Q000378:metabolism; D009994:Osmolar Concentration; D011817:Rabbits; D012542:Scattering, Radiation
D000199:Actins; D015879:Myosin Subfragments; D000255:Adenosine Triphosphate; D000205:Actomyosin; D000251:Adenosine Triphosphatases; D008274:Magnesium