Ions and energy in mammalian brain.

Pyruvate kinase: Function, regulation and role in cancer.

Isoelectric points of proteins: A table

The product of the incorporation of [14C]tyrosine as single unit into a protein of the soluble fraction of rat brain homogenate was purified by following a procedure used to purify tubulin. Sodium dodecylsulphate-polyacrylamide gel electrophoresis of the purified material showed a single protein band containing all the radioactivity. Purification data indicate that this protein accounts for 10.2% of the total protein of the supernatant fraction. This is in good agreement with the amount found for tubulin by the [3H]colchicine-binding method (10.5% of the total protein). The incorporated [14C]-tyrosine was found in the alpha-subunit of tubulin. Protein labelled with [3H]colchicine and [14C]tyrosine was precipatated with vinblastine sulphate and the radioactivity of 3H and that of 14C were quantitatively recovered in the precipitate (98%). Sodium dodecylsulphate-polyacrylamide gel electrophoresis of the vinblastine precipitate showed that the 14C radioactivity moved with the tubulin band. Results obtained in experiments with phenylalanine and 3,4-dihydroxyphenylalanine were identical to those obtained for tyrosine. Bineing of colchicine did not interfere with the incorporation of tyrosine. About 30% of tubulin from rat brain supernatant fraction can incorporate tyrosine as single unit.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1975.tb02435.x

Incorporation of l‐Tyrosine, l‐Phenylalanine and l‐3,4‐Dihydroxyphenylalanine as Single Units into Rat Brain Tubulin

Isozymes of pyruvate kinase in vertebrates: their physical, chemical, kinetic and immunological properties

Bovine Pyruvate Kinases I. PURIFICATION AND CHARACTERIZATION OF THE SKELETAL MUSCLE ISOZYME

Bovine pyruvate kinase isozymes and hybrid isozymes. Electrophoretic studies and tissue distribution.

Tissues of fetal and adult chickens were examined for pyruvate kinase activity. Two electrophoretically distinguishable and noninterconvertible isozymes were found. One of these, designated as type K (for kidney), is the sole pyruvate kinase in the early fetus and is found in appreciable quantities in all adult tissues except striated muscle. The second isozyme, type M, appears shortly before hatching in striated muscle and brain. These two isozymes correspond in their developmental pattern, tissue distribution, electrophoretic, immunological, and kinetic propertiesto similarly designated mammalian pyruvate kinases. However, no kinetic, immunological, or electrophoretic evidence could be found for a chicken isozyme corresponding to the mammalian type L pyruvate kinase. As the latter isozyme seems to be limited in its distribution mostly to highly differentiated gluconeogenic tissues (notable liver, kidney, and small intestine), our results support the proposition that the mammalian type L pyruvate kinase is a specilized isozyme that is present in mammals but not in birds.

Pyruvate kinase isozymes in adult and fetal tissues of chicken.

Effects of phenylalanine and alanine on the kinetics of bovine pyruvate kinase isoenzymes

. Bovine tissues, like those of other mammals, contain at least three non-interconvertible pyruvate kinase isozymes, designated type K or K 4 , type L or L 4 , and type M or M 4 . The K- and L-type isozymes have sigmoidal kinetics with P-enolpyruvate and are activated by fructose 1,6-diphos-phate, while type M pyruvate kinase has hyperbolic kinetics even in the absence of fructose diphosphate.

J. Jeffrey Strandholm

Papers

Bovine Pyruvate Kinases I. PURIFICATION AND CHARACTERIZATION OF THE SKELETAL MUSCLE ISOZYME

Bovine pyruvate kinase isozymes and hybrid isozymes. Electrophoretic studies and tissue distribution.

Pyruvate kinase isozymes in adult and fetal tissues of chicken.

Effects of phenylalanine and alanine on the kinetics of bovine pyruvate kinase isoenzymes

Bovine and chicken pyruvate kinase isozymes intraspecies and interspecies hybrids