Crystal structure of human carbonic anhydrase II complexed with ananti-convulsant sugar sulphamate

2002 ◽  
Vol 361 (3) ◽  
pp. 437-441 ◽  
Author(s):  
Rosario RECACHA ◽  
Michael J. COSTANZO ◽  
Bruce E. MARYANOFF ◽  
Debasish CHATTOPADHYAY
Keyword(s):  
Carbonic Anhydrase ◽  
Oxygen Atom ◽  
Active Site ◽  
Enzyme Inhibitor ◽  
Bound Water ◽  
Zinc Ion ◽  
Carbonic Anhydrase Ii ◽  
Sulphate Group ◽  
X Ray Crystallography ◽  
Human Carbonic Anhydrase

The fructose-based sugar sulphamate RWJ-37497, a potent analogue of the widely used anti-epileptic drug topiramate, possesses anti-convulsant and carbonic anhydrase-inhibitory activities. We have studied the binding interactions of RWJ-37497 in the active site of human carbonic anhydrase II by X-ray crystallography. The atomic positions of the enzyme inhibitor complex were refined at a resolution of 2.1 Å (1 Å = 0.1 nm) to the final crystallographic R and Rfree values of 0.18 and 0.23, respectively. The inhibitor co-ordinates to the active-site zinc ion through its oxygen atom and the ionized nitrogen atom of the sulphamate group by replacing the metal-bound water molecules, although the sulphamoyl oxygen atom provides a rather lengthyco-ordination. The 4,5-cyclic sulphate group is positioned in a hydrophobic pocket of the active site, making contacts with the residues Phe-131, Leu-198, Pro-201 and Pro-202. Since the ligand was found to be intact, concerns about RWJ-37947 irreversibly alkylating the enzyme through its 4,5-cyclic sulphate group were dispelled.

scholarly journals Active-site solvent replenishment observed during human carbonic anhydrase II catalysis

IUCrJ ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Jin Kyun Kim ◽  
Carrie L. Lomelino ◽  
Balendu Sankara Avvaru ◽  
Brian P. Mahon ◽  
Robert McKenna ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Proton Transfer ◽  
Active Site ◽  
Water Reservoir ◽  
Bound Water ◽  
Nucleophilic Attack ◽  
Carbonic Anhydrase Ii ◽  
Intermediate Water ◽  
Water Network ◽  
Human Carbonic Anhydrase

Human carbonic anhydrase II (hCA II) is a zinc metalloenzyme that catalyzes the reversible hydration/dehydration of CO2/HCO3 −. Although hCA II has been extensively studied to investigate the proton-transfer process that occurs in the active site, its underlying mechanism is still not fully understood. Here, ultrahigh-resolution crystallographic structures of hCA II cryocooled under CO2 pressures of 7.0 and 2.5 atm are presented. The structures reveal new intermediate solvent states of hCA II that provide crystallographic snapshots during the restoration of the proton-transfer water network in the active site. Specifically, a new intermediate water (WI′) is observed next to the previously observed intermediate water WI, and they are both stabilized by the five water molecules at the entrance to the active site (the entrance conduit). Based on these structures, a water network-restructuring mechanism is proposed, which takes place at the active site after the nucleophilic attack of OH− on CO2. This mechanism explains how the zinc-bound water (WZn) and W1 are replenished, which are directly responsible for the reconnection of the His64-mediated proton-transfer water network. This study provides the first `physical' glimpse of how a water reservoir flows into the hCA II active site during its catalytic activity.

scholarly journals Azobenzene-based inhibitors of human carbonic anhydrase II

2015 ◽  
Vol 11 ◽  
pp. 1129-1135 ◽  
Author(s):  
Leander Simon Runtsch ◽  
David Michael Barber ◽  
Peter Mayer ◽  
Michael Groll ◽  
Dirk Trauner ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Catalytic Activity ◽  
Carbonic Anhydrase ◽  
Drug Class ◽  
Carbonic Anhydrase Ii ◽  
Carbonic Anhydrases ◽  
X Ray ◽  
X Ray Crystallography ◽  
Human Carbonic Anhydrase

Aryl sulfonamides are a widely used drug class for the inhibition of carbonic anhydrases. In the context of our program of photochromic pharmacophores we were interested in the exploration of azobenzene-containing sulfonamides to block the catalytic activity of human carbonic anhydrase II (hCAII). Herein, we report the synthesis and in vitro evaluation of a small library of nine photochromic sulfonamides towards hCAII. All molecules are azobenzene-4-sulfonamides, which are substituted by different functional groups in the 4´-position and were characterized by X-ray crystallography. We aimed to investigate the influence of electron-donating or electron-withdrawing substituents on the inhibitory constant K i. With the aid of an hCAII crystal structure bound to one of the synthesized azobenzenes, we found that the electronic structure does not strongly affect inhibition. Taken together, all compounds are strong blockers of hCAII with K i = 25–65 nM that are potentially photochromic and thus combine studies from chemical synthesis, crystallography and enzyme kinetics.

Out of the active site binding pocket for carbonic anhydrase inhibitors

2015 ◽  
Vol 51 (2) ◽  
pp. 302-305 ◽  
Author(s):  
Katia D'Ambrosio ◽  
Simone Carradori ◽  
Simona M. Monti ◽  
Martina Buonanno ◽  
Daniela Secci ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Active Site ◽  
Binding Pocket ◽  
Carbonic Anhydrase Ii ◽  
Carbonic Anhydrase Inhibitors ◽  
Human Carbonic Anhydrase ◽  
Site Binding

2-Benzylsulfinylbenzoic acid binds to human carbonic anhydrase II in a mode completely different from any other class of carbonic anhydrase inhibitors investigated so far.

scholarly journals Effect of Active-site Mutation at Asn67 on the Proton Transfer Mechanism of Human Carbonic Anhydrase II

Biochemistry ◽  
2009 ◽  
Vol 48 (33) ◽  
pp. 7996-8005 ◽  
Author(s):  
C. Mark Maupin ◽  
Jiayin Zheng ◽  
Chingkuang Tu ◽  
Robert McKenna ◽  
David N. Silverman ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Proton Transfer ◽  
Active Site ◽  
Transfer Mechanism ◽  
Carbonic Anhydrase Ii ◽  
Site Mutation ◽  
Human Carbonic Anhydrase

scholarly journals Importance of C-Terminal Knot Structure in Carbonic Anhydrase II (Part I): Role of C-Terminal Knot Forming GLN253 on Enzymatic Property of Human Carbinic II

1970 ◽  
Vol 14 ◽  
pp. 1-9
Author(s):  
Mohammad Taufiq Alam
Keyword(s):  
Amino Acid ◽  
Carbonic Anhydrase ◽  
Point Mutation ◽  
Amino Acid Residue ◽  
Active Site ◽  
Terminal Region ◽  
Carbonic Anhydrase Ii ◽  
C Terminus ◽  
Human Carbonic Anhydrase

In both, bovine and human carbonic anhydrase II, a conserved glutamine residue occupies the position in the middle of the knot, which is formed by intercrossing of C-terminal end with N-terminal region. Previous studies have indicated that C-terminus is not the part of an active site, but truncation of 7 amino acid residue in this region can have marked effects on stability of the enzyme (data not published). To gain further insight into the role of specific amino acid residue in C-terminal region, site directed mutagenesis was used to introduce point mutation. Substitution of glutamine with cysteine was chosen because the cysteine residue is less hydrophilic as compared with glutamine and thus, may disrupt the hydrophilic environment in this region. Result indicates that Gln253 located within the C-terminus knot topology plays a significant role in normal function of the enzyme. Thus, C-terminal region might mediate cooperativity between the central active site of the enzyme through proper formation of knot. Key words: Human carbonic anhydrase II; knot topology; point mutation J. bio-sci. 14: 1-9, 2006

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