Biomaterial Database

Purification and characterization of human erythrocyte pyridoxine kinase. 1975

C J Chern, and E Beutler

A 6000-fold purification of pyridoxine kinase from human erythrocytes has been achieved by a combination of DEAE-cellulose chromatography, ammonium sulfate fractionation, gel filtration and preparative disc polyacrylamide gel electrophoresis. Analytic disc polyacrylamide gel electrophoresis at pH 8.7 reveals two protein bands with similar mobility in the purified enzyme, but only one of these has catalytic activity. The enzyme is found to have a pI of 5.5 and a molecular weight of 65000 by gel filtration, and a broad pH optimum of 8.5. The enzyme is labile at acidic pH. The order of activation of divalent metal ions on the enzyme is Co-2+ greater than Mn-2+ greater than Mg-2+ greater than Zn-2+ greater than Cu-2+ greater than Ni-2+ greater than Fe-2+. Of the monovalent cations studied, K+ is the most effective activator, NH+4 is slightly less effective while Na+ is inhibitory. ATP is the specific phosphate donor for the enzyme. Sulfhydryl reagents did not significantly inhibit the enzyme. The Km for pyridoxine is 5.7 with 10-minus 6 M. Pyridoxal, pyridoxamine and 4-deoxypyridoxine inhibit pyridoxine kinase. Inhibition by pyridoxal is competitive and pyridoxal is observed to be phosphorylated effectively by the enzyme. Young human red cells have a higher activity of pyridoxine kinase than old red cells.

UI	MeSH Term	Description	Entries
D007525	Isoelectric Focusing	Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.	Electrofocusing,Focusing, Isoelectric
D007526	Isoelectric Point	The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.	Isoelectric Points,Point, Isoelectric,Points, Isoelectric
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010770	Phosphotransferases	A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.	Kinases,Phosphotransferase,Phosphotransferases, ATP,Transphosphorylase,Transphosphorylases,Kinase,ATP Phosphotransferases
D011730	Pyridoxal	The 4-carboxyaldehyde form of VITAMIN B 6 which is converted to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid.
D011733	Pyridoxamine	The 4-aminomethyl form of VITAMIN B 6. During transamination of amino acids, PYRIDOXAL PHOSPHATE is transiently converted into pyridoxamine phosphate.
D011736	Pyridoxine	The 4-methanol form of VITAMIN B 6 which is converted to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990).	Pyridoxin,Pyridoxine Hydrochloride,Pyridoxol,Pyridoxol Hydrochloride,Rodex
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D002414	Cations, Monovalent	Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.	Monovalent Cation,Cation, Monovalent,Monovalent Cations