Evidence for an inhibitory LIM domain in a rat brain agmatinase-like protein

► Agmatinase-like protein (ALP) is a rat brain enzyme that catalyzes agmatine hydrolysis. ► We analyzed the function of a LIM-domain sequence in this protein. ► The catalytic efficiency was increased by about 30 times by removal of the LIM domain in ALP. ► We propose the LIM sequence as an autoinhib...

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Bibliographic Details
Published in:Archives of biochemistry and biophysics 2011-08, Vol.512 (1), p.107-110
Main Authors: Castro, Víctor, Fuentealba, Pablo, Henríquez, Adolfo, Vallejos, Alejandro, Benítez, José, Lobos, Marcela, Díaz, Beatriz, Carvajal, Nelson, Uribe, Elena
Format: Article
Language:English
Subjects:
Agmatinase
Agmatine
Agmatine - metabolism
Amino acid sequence
amino acid sequences
Animals
Astrocytes
Brain
Brain - enzymology
Consensus Sequence
fluorescence
Hippocampus
Hypothalamus
immunohistochemistry
Kinetics
LIM domain
LIM protein
Monomers
Neurons
Polyamines
Protein Structure, Tertiary
Rats
Sequence Deletion
Tryptophan
Ureohydrolases - chemistry
Ureohydrolases - genetics
Ureohydrolases - metabolism
Zinc
Zinc Fingers
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Summary:► Agmatinase-like protein (ALP) is a rat brain enzyme that catalyzes agmatine hydrolysis. ► We analyzed the function of a LIM-domain sequence in this protein. ► The catalytic efficiency was increased by about 30 times by removal of the LIM domain in ALP. ► We propose the LIM sequence as an autoinhibitory domain in ALP. 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 (∼2 Zn 2+/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.
ISSN:0003-9861
1096-0384
DOI:10.1016/j.abb.2011.05.003