[Modification of RNA ligase histidine residues by diethylpyrocarbonate].
The practicality of Tris-HCl buffer for modification of histidine residues by diethylpyrocarbonate (DEPC) was studied using a model protein-hexokinase. It was found that modification was selective at pH 7.5. Conditions for modification of one histidine residue in the protein molecule were specified. In 30 mM Tris-HCl buffer pH 7.5, 10-min interaction of RNA-ligase with 0.3 mM DEPC was accompanied by modification of one histidine residue, as a result of which the ability to form a covalent AMP-RNA-ligase complex decreased 3 times. Modification of two histidine residues of RNA-ligase resulted in a complete loss of the enzyme activity. At increasing DEPC concentration modification affected all of the seven histidine residues of RNA-ligase. The kinetic parameters (Km and V) for the native and modified enzymes were determined and compared.
Sabaliauskene
V
V
Department of Biochemistry, University of Debreczen, Hungary.
Kish
L
L
Iuodka
B
B
D004047:Diethyl Pyrocarbonate / Q000737:chemistry*; D006593:Hexokinase / Q000737:chemistry / Q000378:metabolism; D006639:Histidine / Q000737:chemistry*; D011130:RNA Ligase (ATP) / Q000037:antagonists & inhibitors / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000201:enzymology
D006639:Histidine; D006593:Hexokinase; D011130:RNA Ligase (ATP); D004047:Diethyl Pyrocarbonate
Modifikatsiia gistidinovykh ostatkov RNK-ligazy diétilpirokarbonatom.