Proteins and enzyme activities of press juices, obtained by ultracentrifugation of white, red and heart muscles of the rabbit

Rabbit muscle myogen. Interactions with phosphate as the source of non-enantiography in moving-boundary electrophoresis

“…In the present investigation of myosin-free myogen from rabbit muscle we confirm the earlier result (Amberson et al, 1964) that the ascending and descending electrophoreticpatternsaredecidedlynonenantiographic, a characteristic ofreversibly associating systems (Gilbert & Jenkins, 1959). However, the phenomenon is shown to result from reversible phosphate binding to, and not from intermolecular association of, myogen components.…”

“…In the previous electrophoretic study (Amberson et at., 1964) decidedly non-enantiographic and complex patterns were obtained from myogen in 0.01 87M-potassium phosphate, pH7.7 (0.0164M-K2HPO4/ 0.0023M-KH2PO4). This non-enantiography and also the complexity of the patterns were absent from experiments performed with myogen in 0.15M-phosphate, pH7.7 (0.134M-K2HPO4/0.0186M-KH2PO4).…”

“…Experimental support for the existence of interactions between different glycolytic enzymes has been inferred from kinetic (Garfinkel & Hess, 1964;Reed & Cox, 1966), velocity sedimentation (Clarke & Masters, 1973), gel chromatography (F6ldi et al, 1973 and electrophoretic (Amberson et al, 1964) studies. From the biological viewpoint this concept of myogen itself as a multi-enzyme complex has been made largely redundant by the detection of interactions between most of the individual glycolytic enzymes and the fibrous components of muscle (Arnold & Pette, 1968;Amberson & Bauer, 1971; Clarke & Masters, 1975).…”

“…Indeed, Clarke & Masters (1974) have attributed their earlier ultracentrifugal evidence of complex-formation in myogen (Clarke & Masters, 1973) to the presence of myosin in the preparation. At this stage the evidence ofreversible association derived from moving-boundary electrophoresis of myogen (Amberson et al, 1964) remains unquestioned.…”

Interaction between D‐Fructose‐1,6‐bisphosphate aldolase and triosephosphate isomerase

“…D-Fructose-l,6-bisphosphate aldolase may participate in the formation of heterologous complexes with glycolytic and gluconeogenetic enzymes: Myogen, a sarcoplasmic preparation rich in glycolytic enzymes, forms a single slow-moving peak in boundary electrophoresis [1 ]; one of its fractions (myogen A)which contains aldolase and glycerophosphate dehydrogenase crystallizes readily and seems to be homogeneous in sedimentation equilibrium analysis [2]. Physicochemical evidence has been provided for interaction between rabbit muscle aldolase and D-glyceraldehyde-3-phosphate dehydrogenase [3], rabbit muscle aldolase and glycerophosphate dehydrogenase [4], rabbit liver aldolase and fructose-l,6-bisphosphatase [5,6], and insect muscle aldolase and triosephosphate isomerase [7].…”