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solution structure of hIFABP V60C/Y70C variant.solution structure of hIFABP V60C/Y70C variant.
Structural highlights
Function[FABPI_HUMAN] FABP are thought to play a role in the intracellular transport of long-chain fatty acids and their acyl-CoA esters. FABP2 is probably involved in triglyceride-rich lipoprotein synthesis. Binds saturated long-chain fatty acids with a high affinity, but binds with a lower affinity to unsaturated long-chain fatty acids. FABP2 may also help maintain energy homeostasis by functioning as a lipid sensor. Publication Abstract from PubMedFatty acid binding proteins play an important role in the transportation of fatty acids. Despite intensive studies, how fatty acids enter the protein cavity for binding is still controversial. Here, a gap-closed variant of human intestinal fatty acid binding protein was generated by mutagenesis, in which the gap is locked by a disulfide bridge. According to its structure determined here by NMR, this variant has no obvious openings as the ligand entrance and the gap cannot be widened by internal dynamics. Nevertheless, it still takes up fatty acids and other ligands. NMR relaxation dispersion, chemical exchange saturation transfer, and hydrogen-deuterium exchange experiments show that the variant exists in a major native state, two minor native-like states, and two locally unfolded states in aqueous solution. Local unfolding of either betaB-betaD or helix 2 can generate an opening large enough for ligands to enter the protein cavity, but only the fast local unfolding of helix 2 is relevant to the ligand entry process. Ligand Entry into Fatty Acid Binding Protein via Local Unfolding Instead of Gap Widening.,Xiao T, Lu Y, Fan JS, Yang D Biophys J. 2020 Jan 21;118(2):396-402. doi: 10.1016/j.bpj.2019.12.005. Epub 2019 , Dec 14. PMID:31870540[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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