Site-specific mutagenesis of aspartate aminotransferase.
نویسندگان
چکیده
منابع مشابه
Aspartate aminotransferase of E. coli: effects of site-directed mutagenesis on substrate recognition.
R292 is crucial for both the binding and the catalysis of the transamination reaction of dicarboxylic acid substrates. Substitution of R292 to uncharged residues greatly enhanced the catalytic efficiency of transamination of neutral amino acids without any effect on the binding. Residues at position 292 may not be involved in recognition of the neutral side chain. The indole ring of W140 not on...
متن کاملSite-specific methylation of a strategic lysyl residue in aspartate aminotransferase.
Conditions for reductive methylation of amine groups in proteins using formaldehyde and cyanoborohydride can be chosen to modify selectively the active site lysyl residue of aspartate aminotransferase among the 19 lysyl residues in each subunit of this protein. Apoenzyme must be treated, under mildly acidic conditions (pH = 6), at a relatively low molar ratio of formaldehyde to protein (40:1); ...
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Aspartate aminotransferases (AspATs; EC 2.6.1.1) catalyze the conversion of aspartate and α-ketoglutarate into oxaloacetate and glutamate and are key enzymes in the nitrogen metabolism of all organisms. Recent findings suggest that the plasmodial enzyme [Plasmodium falciparum aspartate aminotransferase (PfAspAT)] may also play a pivotal role in energy metabolism and in the de novo biosynthesis ...
متن کاملPhotoinactivation of aspartate aminotransferase.
The cofactor pyridoxal 5’-phosphate bound through an aldimine linkage to lysine residues of the enzyme aspartate amiuotransferase is very stable to irradiation with light of 420 nm. The catalytic function of the enzyme exposed to light absorbed by the cofactor remains unaffected, indicating that pyridoxal 5’-phosphate is not an efficient active site photosensitizer for this aminotransferase. Th...
متن کاملAcylation of aspartate aminotransferase.
1. Acetylation of aspartate aminotransferase from pig heart inhibits completely the enzymic activity when the coenzyme is in the amino form (pyridoxamine phosphate) or when the coenzyme has been removed, but not when the coenzyme is in the aldehyde form (pyridoxal phosphate). 2. The group the acylation of which is responsible for the inhibition has been identified with the in-amino group of a l...
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ژورنال
عنوان ژورنال: Seibutsu Butsuri
سال: 1988
ISSN: 0582-4052,1347-4219
DOI: 10.2142/biophys.28.7