Inhibition of human arginase I by substrate and product analogues.
Di Costanzo, L., Ilies, M., Thorn, K.J., Christianson, D.W.(2010) Arch Biochem Biophys 496: 101-108
- PubMed: 20153713 
- DOI: https://doi.org/10.1016/j.abb.2010.02.004
- Primary Citation of Related Structures:  
3KV2, 3LP4, 3LP7 - PubMed Abstract: 
Human arginase I is a binuclear manganese metalloenzyme that catalyzes the hydrolysis of L-arginine to generate L-ornithine and urea. We demonstrate that N-hydroxy-L-arginine (NOHA) binds to this enzyme with K(d)=3.6 microM, and nor-N-hydroxy-L-arginine (nor-NOHA) binds with K(d)=517 nM (surface plasmon resonance) or K(d) approximately 50 nM (isothermal titration calorimetry). Crystals of human arginase I complexed with NOHA and nor-NOHA afford 2.04 and 1.55 A resolution structures, respectively, which are significantly improved in comparison with previously-determined structures of the corresponding complexes with rat arginase I. Higher resolution structures clarify the binding interactions of the inhibitors. Finally, the crystal structure of the complex with L-lysine (K(d)=13 microM) is reported at 1.90 A resolution. This structure confirms the importance of hydrogen bond interactions with inhibitor alpha-carboxylate and alpha-amino groups as key specificity determinants of amino acid recognition in the arginase active site.
Organizational Affiliation: 
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.