8GEW

H-FABP crystal soaked in a bromo palmitic acid solution

8GEW の概要

• エントリーDOI: 10.2210/pdb8gew/pdb
• 分子名称: Fatty acid-binding protein, heart, 2-Bromopalmitic acid, OLEIC ACID, ... (4 entities in total)
• 機能のキーワード: h-fabp, br-palmitic acid, lipid binding protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 15425.72

構造登録者

Howard, E.,Cousido-Siah, A.,Alvarez, A.,Espinosa, Y.,Podjarny, A.,Mitschler, A.,Carlevaro, M. (登録日: 2023-03-07, 公開日: 2023-08-30, 最終更新日: 2024-04-17)

主引用文献

Alvarez, H.A.,Cousido-Siah, A.,Espinosa, Y.R.,Podjarny, A.,Carlevaro, C.M.,Howard, E.
Lipid exchange in crystal-confined fatty acid binding proteins: X-ray evidence and molecular dynamics explanation.
Proteins, 91:1525-1534, 2023

PubMed Abstract: Fatty acid binding proteins (FABPs) are responsible for the long-chain fatty acids (FAs) transport inside the cell. However, despite the years, since their structure is known and the many studies published, there is no definitive answer about the stages of the lipid entry-exit mechanism. Their structure forms a -barrel of 10 anti-parallel strands with a cap in a helix-turn-helix motif, and there is some consensus on the role of the so-called portal region, involving the second -helix from the cap ( 2), C- D, and E- F turns in FAs exchange. To test the idea of a lid that opens, we performed a soaking experiment on an h-FABP crystal in which the cap is part of the packing contacts, and its movement is strongly restricted. Even in these conditions, we observed the replacement of palmitic acid by 2-Bromohexadecanoic acid (Br-palmitic acid). Our MD simulations reveal a two-step lipid entry process: (i) The travel of the lipid head through the cavity in the order of tens of nanoseconds, and (ii) The accommodation of its hydrophobic tail in hundreds to thousands of nanoseconds. We observed this even in the cases in which the FAs enter the cavity by their tail. During this process, the FAs do not follow a single trajectory, but multiple ones through which they get into the protein cavity. Thanks to the complementary views between experiment and simulation, we can give an approach to a mechanistic view of the exchange process.

PubMed: 37462340
DOI: 10.1002/prot.26546

実験手法

X-RAY DIFFRACTION (0.97 Å)