[摘要]：We recently cloned a rat brain agmatinase-like protein (ALP) whose amino acid sequence greatly differs from other agmatinases and exhibits a LIM-like domain close to its carboxyl terminus. The protein was immunohistochemically detected in the hypothalamic region and hippocampal astrocytes and neurons. We now show that truncated species, lacking the LIM-type domain, retains the dimeric structure of the wild-type protein but exhibits a 10-fold increased k(cat), a 3-fold decreased K-m value for agmatine and altered intrinsic tryptophan fluorescent properties. As expected for a LIM protein, zinc was detected only in the wild-type ALP (similar to 2 Zn2+/monomer). Our proposal is that the LIM domain functions as an autoinhibitory entity and that inhibition is reversed by interaction of the domain with some yet undefined brain protein. (c) 2011 Elsevier Inc. All rights reserved.
