On the association of glycolytic enzymes with structural proteins of skeletal muscle.
1. The effects of protein concentration and ionic strength on the adsorption of the individual glycolytic enzymes to F-actin and F-actin--trypomyosin--troponin have been studied. 2. Appreciable association was demonstrated under conditions of physiological ionic strength and high protein concentration, and tropomyosin--troponin established as an important and generalized component of these interactions. 3. Phosphofructokinase, aldolase, pyruvate kinase, lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate isomerase were strongly bound under these conditions, while triosephosphate isomerase, phosphoglycerate kinase, phosphoglycerate mutase, enolase and hexokinase displayed less adsorption to the structural proteins. 4. The influence of a number of parameters on the adsorption phenomena was examined. Ca2+ and fructose 1,6-diphosphate increased the adsorption of aldolase, lactate dehydrogenase and pyruvate kinase, while decreasing the adsorption of the enzymes of the constant-proportion group. 5. Of the other major enzymic components of skeletal muscle, creatine kinase, adenylate kinase and malate dehydrogenase showed no adsorption to F-actin--tropomyosin--troponin under the experimental conditions. Some adsorption was evident, however, in the case of aspartate aminotransferase, (NADP) isocitrate dehydrogenase and alpha-glycerolphosphate dehydrogenase. 6. These results have been discussed in relation to their functional significance and the roles of enzyme compartmentation in the cell.
D000818:Animals; D002417:Cattle; D005634:Fructose-Bisphosphate Aldolase; D006019:Glycolysis; D007770:L-Lactate Dehydrogenase; D009124:Muscle Proteins; D009132:Muscles / Q000201:enzymology*; D009994:Osmolar Concentration; D011485:Protein Binding; D011770:Pyruvate Kinase; D051381:Rats; D012756:Sheep
D009124:Muscle Proteins; D007770:L-Lactate Dehydrogenase; D011770:Pyruvate Kinase; D005634:Fructose-Bisphosphate Aldolase