A new concept in the molecular process of muscle contraction: functional role of phosphorylated amino acids in myosin.
In this report a summary is given of our experiments concerning the in vivo endogenous phosphate (P) content of myosin. It was found that besides the ester type phosphates of myosin there was a considerable amount of N-P type energy-rich phosphoryl groups bond to the basic amino acids of peptide chains. The endogenous P concentration of myosin depends on the source of the preparation. The concentration of P is much higher in myosin preparations of well-trained animals and human subjects compared to those found in the control muscles. As the P binding sites of fresh purified myosin are only partially saturated, the preparations can incorporate P up to a definite saturation only. The phosphorylating ability of myosins disappears after prolonged storage as a consequence of an alteration in structure of the myosin molecule. The P groups are moving inside the myosin molecule. It is supposed that the inorganic P release promoted by actin is connected with the thin filament movements towards the centre of the sarcomere, furthermore P replenishment, P linking and movement involve N3-trimethyl-lysine, 3-methylhistidine, P-Arg and two conformers of P-His. The two net negative charges of P group form electric monopoles of a minor battery (myosin head). They help to force generation at head rotation (90 degrees-45 degrees angle) and produce free energy changes that can be calculated from the number of N-P bonds.
Fazekas
S
S
Second Institute of Biochemistry, Semmelweis University Medical School, Budapest, Hungary.
Berentey
G
G
Fehér
G
G
Székessy-Hermann
V
V
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D005260:Female; D006801:Humans; D009119:Muscle Contraction; D009218:Myosins / Q000378:metabolism / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism*; D010766:Phosphorylation; D011247:Pregnancy / Q000378:metabolism; D014599:Uterus / Q000378:metabolism
D000596:Amino Acids; D010710:Phosphates; D009218:Myosins