Substitution of a conserved amino acid residue alters the ligand binding properties of peroxisome proliferator activated receptors.
Mutation of glutamic acid 282 of PPARalpha to glycine has been shown to result in an increased EC(50) for a wide variety of PPAR activating compounds. This has suggested that mutant receptor has a reduced ability to bind ligand. In this study we show that this mutation reduces the affinity of mPPARalpha and hPPARgamma for the fluorescent fatty acid, cis-parinaric acid and that the mutant hPPARgamma protein has a reduced affinity for the radiolabelled compound, SB236636. These data confirm the role of this glutamic acid in ligand binding and support recent crystal structure observations regarding a proposed novel mode of ligand entry into the PPAR ligand binding cavities.
Causevic
M
M
Biomedical Research Centre, ICRF Molecular Pharmacology Unit, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
Wolf
C R
CR
Palmer
C N
CN
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D004926:Escherichia coli; D005231:Fatty Acids, Unsaturated / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D015870:Gene Expression; D018698:Glutamic Acid / Q000737:chemistry; D006801:Humans; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics
D000596:Amino Acids; D005231:Fatty Acids, Unsaturated; D005456:Fluorescent Dyes; D008024:Ligands; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D018698:Glutamic Acid; C013641:parinaric acid