Purification and inhibition studies with anions and sulfonamides of an alpha-carbonic anhydrase from the Antarctic seal Leptonychotes weddellii.

Article Details

Citation

Cincinelli A, Martellini T, Innocenti A, Scozzafava A, Supuran CT

Purification and inhibition studies with anions and sulfonamides of an alpha-carbonic anhydrase from the Antarctic seal Leptonychotes weddellii.

Bioorg Med Chem. 2011 Mar 15;19(6):1847-51. doi: 10.1016/j.bmc.2011.02.015. Epub 2011 Feb 13.

PubMed ID
21377369 [ View in PubMed
]
Abstract

A high activity alpha-carbonic anhydrase (CA, EC 4.2.1.1) has been purified from various tissues of the Antarctic seal Leptonychotes weddellii. The new enzyme, denominated lwCA, has a catalytic activity for the physiologic CO(2) hydration to bicarbonate reaction, similar to that of the high activity human isoform hCA II, with a k(cat) of 1.1x10(6) s(-1), and a k(cat)/K(m) of 1.4x10(8) M(-1) s(-1). The enzyme was highly inhibited by cyanate, thiocyanate, cyanide, bicarbonate, carbonate, as well as sulfamide, sulfamate, phenylboronic/phenylarsonic acids (K(I)s in the range of 46-100 muM). Many clinically used sulfonamides, such as acetazolamide, methazolamide, dorzolamide, brinzolamide and benzolamide were low nanomolar inhibitors, with K(I)s in the range of 5.7-67 nM. Dichlorophenamide, zonisamide, saccharin and hydrochlorothiazide were weaker inhibitors, with K(I)s in the range of 513-5390 nM. The inhibition profile with anions and sulfonamides of the seal enzyme was rather different from those of the human isoforms hCA I and II. The high sensitivity to bicarbonate inhibition of lwCA, unlike that of the human enzymes, may reflect an evolutionary adaptation to the deep water, high CO(2) partial pressure and hypoxic conditions in which Weddell seals spend much of their life.

DrugBank Data that Cites this Article

Binding Properties
DrugTargetPropertyMeasurementpHTemperature (°C)
5-[(phenylsulfonyl)amino]-1,3,4-thiadiazole-2-sulfonamideCarbonic anhydrase 2Ki (nM)9N/AN/ADetails
AcetazolamideCarbonic anhydrase 1Ki (nM)250N/AN/ADetails
AcetazolamideCarbonic anhydrase 2Ki (nM)12N/AN/ADetails
AcetazolamideCarbonic anhydrase 3Ki (nM)240000N/AN/ADetails
AcetazolamideCarbonic anhydrase 4Ki (nM)74N/AN/ADetails
BrinzolamideCarbonic anhydrase 1Ki (nM)45000N/AN/ADetails
BrinzolamideCarbonic anhydrase 2Ki (nM)3N/AN/ADetails
DiclofenamideCarbonic anhydrase 1Ki (nM)1200N/AN/ADetails
DiclofenamideCarbonic anhydrase 2Ki (nM)38N/AN/ADetails
DorzolamideCarbonic anhydrase 1Ki (nM)50000N/AN/ADetails
DorzolamideCarbonic anhydrase 2Ki (nM)9N/AN/ADetails
EthoxzolamideCarbonic anhydrase 1Ki (nM)25N/AN/ADetails
EthoxzolamideCarbonic anhydrase 2Ki (nM)8N/AN/ADetails
ZonisamideCarbonic anhydrase 1Ki (nM)56N/AN/ADetails
ZonisamideCarbonic anhydrase 2Ki (nM)35N/AN/ADetails