5NU8

Structure of human urine RBP4 saturated with palmitate

Summary for 5NU8

• Entry DOI: 10.2210/pdb5nu8/pdb
• Related: 5NU2
• Descriptor: Retinol-binding protein 4, PALMITIC ACID, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: rbp4, plasma retinol-binding protein, lipocalin, palmitate, transport protein
• Biological source: Homo sapiens (Human)
• Cellular location: Secreted : P02753
• Total number of polymer chains: 1
• Total formula weight: 21311.77

Authors

Perduca, M.,Monaco, H.L.,Galliano, M. (deposition date: 2017-04-28, release date: 2018-03-07, Last modification date: 2024-10-09)

Primary citation

Perduca, M.,Nicolis, S.,Mannucci, B.,Galliano, M.,Monaco, H.L.
Human plasma retinol-binding protein (RBP4) is also a fatty acid-binding protein.
Biochim. Biophys. Acta, 1863:458-466, 2018

PubMed Abstract: RBP4 (plasma retinol-binding protein) is the 21 kDa transporter of all-trans retinol that circulates in plasma as a moderately tight 1:1 molar complex of the vitamin with the protein. RBP4 is primarily synthesized in the liver but is also produced by adipose tissue and circulates bound to a larger protein, transthyretin, TTR, that serves to increase its molecular mass and thus avoid its elimination by glomerular filtration. This paper reports the high resolution three-dimensional structures of human RBP4 naturally lacking bound retinol purified from plasma, urine and amniotic fluid. In all these crystals we found a fatty acid molecule bound in the hydrophobic ligand-binding site, a result confirmed by mass spectrometry measurements. In addition we also report the 1.5 Å resolution structures of human holo-RBP4 and of the protein saturated with palmitic and lauric acid and discuss the interaction of the fatty acids and retinol with the protein.

PubMed: 29414511
DOI: 10.1016/j.bbalip.2018.01.010

Experimental method

X-RAY DIFFRACTION (1.59 Å)