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BioAssay: AID 238544

Inhibition constant of anion against human carbonic anhydrase isozyme hCA IV

The membrane-associated human isozyme of carbonic anhydrase, hCA IV, has been investigated for its interaction with anion inhibitors, for the CO(2) hydration reaction catalyzed by this enzyme. Surprisingly, halides were observed to act as potent hCA IV inhibitors, with inhibition constants in the range of 70-90 microM, although most of these ions, and especially fluoride, the best hCA IV more ..
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 Tested Compounds
 Tested Compounds
All(14)
 
 
Unspecified(14)
 
 
 Tested Substances
 Tested Substances
All(14)
 
 
Unspecified(14)
 
 
 Related BioAssays
 Related BioAssays
AID: 238544
Data Source: ChEMBL (302638)
BioAssay Type: Confirmatory, Concentration-Response Relationship Observed
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2010-05-24
Modify Date: 2014-08-23

Data Table ( Complete ):           View All Data
Target
Sequence: RecName: Full=Carbonic anhydrase 4; AltName: Full=Carbonate dehydratase IV; AltName: Full=Carbonic anhydrase IV; Short=CA-IV; Flags: Precursor
Description ..   
Protein Family: alpha_CA_IV_XV_like
Comment ..   

Gene:CA4     Related Protein 3D Structures     More BioActivity Data..
Tested Compounds:
Description:
Title: Carbonic anhydrase inhibitors: inhibition of the membrane-bound human isozyme IV with anions.

Abstract: The membrane-associated human isozyme of carbonic anhydrase, hCA IV, has been investigated for its interaction with anion inhibitors, for the CO(2) hydration reaction catalyzed by this enzyme. Surprisingly, halides were observed to act as potent hCA IV inhibitors, with inhibition constants in the range of 70-90 microM, although most of these ions, and especially fluoride, the best hCA IV inhibitor among the halides, are weak inhibitors of other isozymes, such as hCA I, II and V. The metal poisons cyanate, cyanide and hydrogen sulfide were weaker hCA IV inhibitors (K(i)'s in the range of 0.6-3.9 mM), whereas thiocyanate, azide, nitrate and nitrite showed even weaker inhibitory properties (K(i)'s in the range of 30.8-65.1 mM). Sulfate was a good hCA IV inhibitor (K(i) of 9 mM), although it is a much weaker inhibitor of isozymes I, II, V and IX. Excellent hCA IV inhibitory properties showed sulfamic acid, sulfamide, phenylboronic acid and phenylarsonic acid, with K(i)'s in the range of 0.87-0.93 microM, whereas their affinities for the other investigated isozymes were in the millimolar range. The interaction of some anions with the mitochondrial isozyme hCA V has also been investigated for the first time here. It has been observed that among all these isozymes, hCA V has the lowest affinity for bicarbonate and carbonate (K(i)'s in the range of 82-95 mM), which may represent an evolutionary adaptation of this isozyme to the rather alkaline environment (pH 8.5) within the mitochondria, where hCA V plays important functions in some biosynthetic reactions involving carboxylating enzymes (pyruvate carboxylase and acetyl coenzyme A carboxylase). There are important differences of affinity for anions between the two membrane-associated isozymes, hCA IV and hCA IX.
(PMID: 15501038)
Categorized Comment - additional comments and annotations
From BioAssay Depositor:
Assay Type: Binding
Target Type: Target is a single protein chain
Assay Data Source: Scientific Literature
Protein Target Class: enzyme lyase
Result Definitions
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TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Ki*Ki PubChem standard valueFloatμM
3BEIBinding Efficiency Index(nM)Float
2SEISurface Efficiency Index(nM)Float
4LELigand EfficiencyFloat
5LLELipophilic Ligand EfficiencyFloat
6Ki activity commentKi activity commentString
7Ki standard flagKi standard flagInteger
8Ki qualifierKi qualifierString
9Ki published valueKi published valueFloatmM
10Ki standard valueKi standard valueFloatnM
11Ki data validityKi data validityString
12Ki binding domainsKi binding domainsString

* Activity Concentration.

Data Table (Concise)
Data Table ( Complete ):     View All Data
Classification
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