Conformational changes of contractile proteins accompanying modulation of skeletal muscle contraction. Polarized microfluorometry investigations.
Results of studies on the modulation of skeletal muscle contraction by phosphorylation of myosin regulatory light chains and by exchange of magnesium for calcium in myosin heads were reviewed. The polarized fluorescence method was used in these studies, and conformational changes of contractile proteins accompanying modulation of skeletal muscle contraction were investigated. It was found that both the exchange of bound magnesium for calcium on myosin heads and the phosphorylation of myosin regulatory light chains control the ability of myosin heads to induce, upon binding to actin, conformational changes of thin filament leading to decrease or increase of its flexibility. The changes in actin filament flexibility may be caused by alteration of both the inter- and the intramonomer structural organization.
Group of Cell Motility, Institute of Cyutology, Academy of Sciences of USSR, Leningrad.
Borovikov YuS
I
I
Kakol
D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D005454:Fluorescence Polarization; D008274:Magnesium / Q000378:metabolism; D009119:Muscle Contraction / Q000502:physiology*; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D010766:Phosphorylation; D011487:Protein Conformation
D000199:Actins; D009124:Muscle Proteins; D009218:Myosins; D008274:Magnesium; D002118:Calcium