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2-chloroacetamidine is an active site-directed, time-dependent inactivator that targets the active-site cysteine residue of DDAH and likely inactivates PAD4 through a similar mechanism. 2-chloroacetamidine may serve as a general pharmacophore for inactivating this superfamily of enzymes and that incorporation of additional functional groups could allow a wide range of application in activity-based protein profiling.

Comprehensive pairwise saturation mutagenesis of the first- and second-shell metal ligands in human arginase I are used to demonstrate the tolerance exhibited by several metal binding ligands towards the amino acid substitutions. The comprehensive saturation mutagenesis analysis of a metallohydrolase active site revealed that the strict conservation of the second-shell metal binding residues in eukaryotic arginases does not reflect kinetic optimization of the enzyme during the course of evolution.

The article explains the structure, bacterial expression, purification, as well as the characterization of the human asparaginase-like protein 1 (hASRGL1). The protein is shown to act as an Ntn hydrolase and hence is shown to be also useful for the removal of accumulation of the toxin peptides in mammalian brain and other tissues.

The mechanism and regulation of dimethylargininase (DDAH) activity is important for developing ways to control nitric oxide production during angiogenesis and in many cases of vascular endothelial pathobiology. The results support a proposed substrate assisted mechanism for Pseudomonas aeruginosa (Pa) DDAH in which ligand binding modulates the reactivity of the active-site cysteine.

A study claims that N-acylhomoserine lactone (AHL) lactonases from Bacillus species 240B1 is not a metalloprotein. However, the gene for an AHL lactonase from Bacillus thuringiensis is cloned and the protein is expressed, purified and found to bind 2 equiv of zinc.

A study is carried out on the dimethylarginine dimethylaminohydrolase (DDAH) that regulates the concentrations of human endogenous inhibitors of nitric oxide synthase, N(sub omega)-methyl-L-arginine (NMMA), and asymmetric N(sub omega), N(sub omega)-dimethyl-L-arginine (ADMA). The studies demonstrate that covalent adduct was attached to an active site residue and implicates Cys249 as the catalytic nucleophile required for intermediate formation.