2NP1

CRYSTAL STRUCTURE OF NITROPHORIN 1 FROM RHODNIUS PROLIXUS

2NP1 の概要

• エントリーDOI: 10.2210/pdb2np1/pdb
• 分子名称: NITROPHORIN 1, AMMONIUM ION, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• 機能のキーワード: nitric oxide transport, ferric heme, antihistamine, vasodilator, lipocalin
• 由来する生物種: Rhodnius prolixus
• 細胞内の位置: Secreted: Q26239
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 42484.76

構造登録者

Weichsel, A.,Montfort, W.R. (登録日: 1998-01-19, 公開日: 1998-05-27, 最終更新日: 2024-11-20)

主引用文献

Weichsel, A.,Andersen, J.F.,Champagne, D.E.,Walker, F.A.,Montfort, W.R.
Crystal structures of a nitric oxide transport protein from a blood-sucking insect.
Nat.Struct.Biol., 5:304-309, 1998

PubMed Abstract: The nitrophorins are heme-based proteins from the salivary glands of the blood-sucking insect Rhodnius prolixus that deliver nitric oxide gas (NO) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. The nitrophorins also bind tightly to histamine, which is released by the host to induce wound healing. Here we present three crystal structures of nitrophorin 1 (NP1): bound to cyanide, which binds in a manner similar to NO (2.3 A resolution); bound to histamine (2.0 A resolution); and bound to what appears to be NH3 from the crystallization solution (2.0 A resolution). The NP1 structures reveal heme to be sandwiched between strands of a lipocalin-like beta-barrel, and in an arrangement unlike any other gas-transport protein discovered to date. The heme is six-coordinate with a histidine (His 59) on the proximal side, and ligand in a spacious pocket on the distal side. The structures confirm that NO and histamine compete for the same binding pocket and become buried on binding. The dissociation constant for histamine binding was found to be 19 nM, approximately 100-fold lower than that for NO.

PubMed: 9546222
DOI: 10.1038/nsb0498-304

実験手法

X-RAY DIFFRACTION (2 Å)