Effects of cryoprotectants on the structure and thermostability of the human carbonic anhydrase II–acetazolamide complex

Journal Article · Wed May 01 04:00:00 EDT 2013 · Acta Crystallographica. Section D: Biological Crystallography

DOI:https://doi.org/10.1107/S0907444913002771· OSTI ID:22351286

Aggarwal, Mayank; Boone, Christopher D.; Kondeti, Bhargav; Tu, Chingkuang; Silverman, David N.; McKenna, Robert ^[1]

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1. University of Florida, 1600 SW Archer Road, PO Box 100245, Gainesville, FL 32610 (United States)

Here, a case study of the effects of cryoprotectants on the kinetics of carbonic anhydrase II (CA II) and its inhibition by the clinically used inhibitor acetazolamide (AZM) is presented. Protein X-ray crystallography has seen a progressive shift from data collection at cool/room temperature (277–298 K) to data collection at cryotemperature (100 K) because of its ease of crystal preparation and the lessening of the detrimental effects of radiation-induced crystal damage, with 20–25%(v/v) glycerol (GOL) being the preferred choice of cryoprotectant. Here, a case study of the effects of cryoprotectants on the kinetics of carbonic anhydrase II (CA II) and its inhibition by the clinically used inhibitor acetazolamide (AZM) is presented. Comparative studies of crystal structure, kinetics, inhibition and thermostability were performed on CA II and its complex with AZM in the presence of either GOL or sucrose. These results suggest that even though the cryoprotectant GOL was previously shown to be directly bound in the active site and to interact with AZM, it affects neither the thermostability of CA II nor the binding of AZM in the crystal structure or in solution. However, addition of GOL does affect the kinetics of CA II, presumably as it displaces the water proton-transfer network in the active site.

• OSTI ID: 22351286
• Journal Information: Acta Crystallographica. Section D: Biological Crystallography, Journal Name: Acta Crystallographica. Section D: Biological Crystallography Journal Issue: Pt 5 Vol. 69; ISSN ABCRE6; ISSN 0907-4449
• Country of Publication: Denmark
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
CRYSTALS
DAMAGE
GLYCEROL
KINETICS
MATHEMATICAL SOLUTIONS
PROTONS
SACCHAROSE
SOLUTIONS
WATER