title: The isolation and characterisation of guinea-pig polymorphonuclear leucocyte actin and myosin.
abstract: The contractile proteins actin and myosin have been isolated from the soluble phase of guinea-pig polymorphonuclear leucocytes and partially characterised. Two forms of actin have been identified, designated 'Mg-actin' and 'KCl-actin'. They have different polymerising properties but their propensity to form synthetic homologous and heterologous actomyosins and to inhibit DNAase-1 does not significantly differ. Both show beta and gamma isoelectric forms in focusing gels and the Mg-actin accounts for about 5% of the soluble-phase protein and te KCl-actin around 2%. Leucocyte myosin has been isolated by affinity chromatography on N6-ADP-Sepharose with a good enrichment of both Ca2+-ATPase and the ATPase activity measured in the absence of Ca2+ or Mg2+ and in the presence of EDTA. This protein, too, has the capacity to form synthetic homologous and hybrid actomyosins with enhancement of the basal Mg2+-ATPase activity. The ratio of actin to myosin in the leucocyte calculated on a molar basis is well in excess of 100, a figure consistent with the findings from other non-muscle cells.
mesh_terms: D000199:Actins / Q000097:blood* / Q000302:isolation & purification; D000251:Adenosine Triphosphatases / Q000097:blood; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases / Q000097:blood; D003850:Deoxyribonuclease I; D003851:Deoxyribonucleases / Q000037:antagonists & inhibitors; D004492:Edetic Acid / Q000494:pharmacology; D004720:Endonucleases / Q000037:antagonists & inhibitors; D006168:Guinea Pigs; D008297:Male; D008854:Microscopy, Electron; D009218:Myosins / Q000097:blood* / Q000302:isolation & purification; D009504:Neutrophils / Q000201:enzymology*; D010446:Peptide Fragments / Q000032:analysis; D014357:Trypsin
chemical_list: D000199:Actins; D000596:Amino Acids; D010446:Peptide Fragments; D004492:Edetic Acid; D003851:Deoxyribonucleases; D004720:Endonucleases; D003850:Deoxyribonuclease I; D014357:Trypsin; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins; D000252:Calcium-Transporting ATPases