1AVN

HUMAN CARBONIC ANHYDRASE II COMPLEXED WITH THE HISTAMINE ACTIVATOR

1AVN の概要

• エントリーDOI: 10.2210/pdb1avn/pdb
• 分子名称: CARBONIC ANHYDRASE II, ZINC ION, MERCURY (II) ION, ... (6 entities in total)
• 機能のキーワード: lyase, oxo-acid
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm : P00918
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 29577.03

構造登録者

Briganti, F.,Mangani, S.,Orioli, P.,Scozzafava, A.,Vernaglione, G.,Supuran, C.T. (登録日: 1997-09-17, 公開日: 1997-12-24, 最終更新日: 2024-02-07)

主引用文献

Briganti, F.,Mangani, S.,Orioli, P.,Scozzafava, A.,Vernaglione, G.,Supuran, C.T.
Carbonic anhydrase activators: X-ray crystallographic and spectroscopic investigations for the interaction of isozymes I and II with histamine.
Biochemistry, 36:10384-10392, 1997

PubMed Abstract: The interaction of native and Co(II)-substituted isozymes I and II of carbonic anhydrase (CA) with histamine, a well-known activator, was investigated kinetically, spectroscopically, and X-ray crystallographically. This activator is of the noncompetitive type with 4-nitrophenyl acetate and CO2 as substrates for both HCA I and HCA II. The electronic spectrum of the adduct of Co(II)-HCA II with histamine is similar to the spectrum of the Co(II)-HCA II-phenol adduct, being only slightly different from that of the uncomplexed enzyme. This is the first spectroscopic evidence that the activator molecule binds within the active site, but not directly to the metal ion. X-ray crystallographic data for the adduct of HCA II with histamine showed that the activator molecule is bound at the entrance of the active site cavity in a position where it may actively participate in shuttling protons between the active site and the bulk solvent. The role of the activators and the reported X-ray crystal structure of the HCA II-histamine adduct has prompted us to reexamine the X-ray structures of the different CA isozymes in order to find a structural basis accounting for their large differences in catalytic rate. A tentative explanation is proposed on the basis of possible pathways of proton transfer, which constitute the rate-limiting step in the catalytic reaction.

PubMed: 9265618
DOI: 10.1021/bi970760v

実験手法

X-RAY DIFFRACTION (2 Å)