GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com


Jump to: navigation, search

López, V, Alarcón, R, Orellana, MS, Enríquez, P, Uribe, E, Martínez, J and Carvajal, N (2005) Insights into the interaction of human arginase II with substrate and manganese ions by site-directed mutagenesis and kinetic studies. Alteration of substrate specificity by replacement of Asn149 with Asp. FEBS J. 272:4540-8


To examine the interaction of human arginase II (EC with substrate and manganese ions, the His120Asn, His145Asn and Asn149Asp mutations were introduced separately. About 53% and 95% of wild-type arginase activity were expressed by fully manganese activated species of the His120Asn and His145Asn variants, respectively. The K(m) for arginine (1.4-1.6 mM) was not altered and the wild-type and mutant enzymes were essentially inactive on agmatine. In contrast, the Asn149Asp mutant expressed almost undetectable activity on arginine, but significant activity on agmatine. The agmatinase activity of Asn149Asp (K(m) = 2.5 +/- 0.2 mM) was markedly resistant to inhibition by arginine. After dialysis against EDTA, the His120Asn variant was totally inactive in the absence of added Mn(2+) and contained < 0.1 Mn(2+).subunit(-1), whereas wild-type and His145Asn enzymes were half active and contained 1.1 +/- 0.1 Mn(2+).subunit(-1) and 1.3 +/- 0.1 Mn(2+).subunit(-1), respectively. Manganese reactivation of metal-free to half active species followed hyperbolic kinetics with K(d) of 1.8 +/- 0.2 x 10(-8) M for the wild-type and His145Asn enzymes and 16.2 +/- 0.5 x 10(-8) m for the His120Asn variant. Upon mutation, the chromatographic behavior, tryptophan fluorescence properties (lambda(max) = 338-339 nm) and sensitivity to thermal inactivation were not altered. The Asn149-->Asp mutation is proposed to generate a conformational change responsible for the altered substrate specificity of arginase II. We also conclude that, in contrast with arginase I, Mn(2+) (A) is the more tightly bound metal ion in arginase II.


PubMed Online version:10.1111/j.1742-4658.2005.04874.x


Amino Acid Substitution; Arginase/genetics; Arginase/metabolism; Base Sequence; DNA/genetics; Humans; Kinetics; Manganese/metabolism; Mutagenesis, Site-Directed; Recombinant Proteins/genetics; Recombinant Proteins/metabolism; Substrate Specificity



Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status


GO:0004053: arginase activity



figure 2

CACAO 4514



GO:0004053: arginase activity

ECO:0000315: mutant phenotype evidence used in manual assertion


Seeded From UniProt


See also


See Help:References for how to manage references in GONUTS.