Inhibition of the lepidopteran amino acid co-transporter KAAT1 by phenylglyoxal: role of arginine 76.
Insect Mol Biol
; 11(4): 283-9, 2002 Aug.
Article
in En
| MEDLINE
| ID: mdl-12144692
ABSTRACT
Phenylglyoxal (PGO), an arginine-modifying reagent, is an irreversible inhibitor of KAAT1-mediated leucine transport, expressed in Xenopus oocytes. The PGO effect was dose-dependent and 5 mm PGO determined a V(max) reduction to 24% of the control, consistent with the covalent binding to transporter arginine residues not located in the leucine binding site. The use of labelled [(14)C]PGO confirmed that the inhibitor binds KAAT1. The protein membrane domain contains seven arginine residues one of which, arginine 76, is conserved in the family of GABA transporters. Using site-directed mutagenesis we showed that only arginine 76 is crucial for KAAT1 activity and is involved in PGO binding.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phenylglyoxal
/
Arginine
/
Biological Transport
/
Membrane Glycoproteins
/
Carrier Proteins
/
Insect Proteins
/
Amino Acid Transport Systems, Neutral
/
Lepidoptera
Limits:
Animals
Language:
En
Journal:
Insect Mol Biol
Journal subject:
BIOLOGIA MOLECULAR
Year:
2002
Document type:
Article
Affiliation country:
Italy