1B56

HUMAN RECOMBINANT EPIDERMAL FATTY ACID BINDING PROTEIN

Summary for 1B56

• Entry DOI: 10.2210/pdb1b56/pdb
• Descriptor: FATTY ACID BINDING PROTEIN, PALMITIC ACID (3 entities in total)
• Functional Keywords: lipid-binding, fatty acid transport, beta barrel, lipid binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm: Q01469
• Total number of polymer chains: 1
• Total formula weight: 15441.88

Authors

Van Tilbeurgh, H.,Hohoff, C.,Borchers, T.,Spener, F. (deposition date: 1999-01-12, release date: 1999-10-05, Last modification date: 2024-11-20)

Primary citation

Hohoff, C.,Borchers, T.,Rustow, B.,Spener, F.,van Tilbeurgh, H.
Expression, purification, and crystal structure determination of recombinant human epidermal-type fatty acid binding protein.
Biochemistry, 38:12229-12239, 1999

PubMed Abstract: We describe the crystal structure of human epidermal-type fatty acid binding protein (E-FABP) that was recently found to be highly upregulated in human psoriatic keratinocytes. To characterize E-FABP with respect to ligand-binding properties and tertiary structure, we cloned the respective cDNA, overexpressed the protein in Escherichia coli and purified it to homogeneity by a combination of ion-exchange and size-exclusion chromatographic steps with a yield of 30 mg/L broth. The purified protein revealed a 5-fold higher affinity for stearic acid than for oleic and arachidonic acids. The crystal structure of recombinant human E-FABP was determined to 2.05 A and refined to an R(factor) of 20.7%. The initial residual electron density maps clearly showed the presence of a ligand, which was identified as endogenous bacterial fatty acid. Within a central cavity of 252 A(3), this ligand is bound in a U-shaped conformation, its carboxyl group interacting with tyrosine 131 and arginines 129 and 109, the latter via an ordered water molecule. The E-FABP crystal structure is unique in the FABP family because of the presence of a disulfide bridge between cysteines 120 and 127 that may be physiologically as well as pathophysiologically relevant. Cysteines 67 and 87 are also in close vicinity but in contrast do not form a disulfide bridge. We postulate that this protein belongs to a particular FABP subfamily whose members share common structural as well as functional features.

PubMed: 10493790
DOI: 10.1021/bi990305u

Experimental method

X-RAY DIFFRACTION (2.05 Å)