Structure of human carbonic anhydrase B

Kannan, K. K.; Fridborg, K.; Bergstén, P.-C.; Liljas, Anders; Lövgren, Seved; Petef, M.; Strandberg, B.; Waara, I.; Adler, Lennart; Falkbring, S.O.; Göthe, P.O.; Nyman, Per Olof

doi:10.1016/0022-2836(72)90452-4

Cited by 26 publications

(6 citation statements)

References 7 publications

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“…6) thus resemble those in unliganded CA. For native enzyme, the values of 18% a-helix and 35.7% b-sheets closely agree with the 20% and 37% values evaluated from X-ray diffraction [38].…”

Section: Discussionsupporting

confidence: 77%

Interactions between carbonic anhydrase and its inhibitors revealed by gel electrophoresis and circular dichroism

et al. 2000

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“…6) thus resemble those in unliganded CA. For native enzyme, the values of 18% a-helix and 35.7% b-sheets closely agree with the 20% and 37% values evaluated from X-ray diffraction [38].…”

Section: Discussionsupporting

confidence: 77%

Interactions between carbonic anhydrase and its inhibitors revealed by gel electrophoresis and circular dichroism

et al. 2000

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“…), Cd II , Co II , Cu II , Fe II , Hg II , Mn II , and Ni II . In III from InCl 3 also binds to the active site of apo -BCA II. , HCA II has been crystallized incorporating Co II , Cu II , Hg II , Mn II , and Ni II ions. ,,,,, …”

Section: Metalloenzyme Variantsmentioning

confidence: 99%

Carbonic Anhydrase as a Model for Biophysical and Physical-Organic Studies of Proteins and Protein−Ligand Binding

et al. 2008

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I. Introduction to Carbonic Anhydrase (CA) and to the Review 948 1. Introduction: Overview of CA as a Model 948 1.1. Value of Models 950 1.2. Objectives and Scope of the Review 950 2. Overview of Enzymatic Activity 950 3. Medical Relevance 951 II. Structure and Structure−Function Relationships of CA 953 4. Global and Active-Site Structure 953 4.1. Structure of Isoforms 953 4.2. Isolation and Purification 954 4.3. Crystallization 954 4.4. Structures Determined by X-ray Crystallography and NMR 955 4.4.1. Structures Determined by X-ray Crystallography 955 4.4.2. Structure Determined by NMR 955 4.5. Global Structural Features 963 4.6. Structure of the Binding Cavity 964 4.7. Zn II -Bound Water 965 5. Metalloenzyme Variants 966 6. Structure−Function Relationships in the Catalytic Active Site of CA 968 6.1. Effects of Ligands Directly Bound to Zn II 968 6.2. Effects of Indirect Ligands 969 7. Physical-Organic Models of the Active Site of CA 969 III. Using CA as a Model to Study Protein−Ligand Binding 970 8. Assays for Measuring Thermodynamic and Kinetic Parameters for Binding of Substrates and Inhibitors 970 8.1. Overview 970 8.

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“…Human carbonic anhydrase B crystallizes in the orthorhombic space group P212,2, with four molecules per unit cell of dimensions a = 81.5, b = 73.6, c = 37.1 A (18,20).…”

Section: Methodsmentioning

confidence: 99%

“…The enzyme was further purified by electrophoresis and on a Sulfur-ethylsephadex C-50 ion exchange column. Crystals of the native enzyme were prepared from 2.3 M ammonium sulfate, pH 8.7, by a seeding technique in small, thick-walled glass capillaries as described (18). Heavy atom derivatives were prepared by soaking native enzyme crystals for at least a week in 2.3 M ammonium sulfate solution, pH 8.7, containing 1 mM heavy atom salts, K2Au(CN)2, * This is paper II in a series.…”

Section: Methodsmentioning

confidence: 99%

Crystal structure of human erythrocyte carbonic anhydrase B. Three-dimensional structure at a nominal 2.2-A resolution.

Kannan¹,

Notstrand²,

Fridborg³

et al. 1975

Proc. Natl. Acad. Sci. U.S.A.

242

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The three- Two major forms of carbonic anhydrase occur in human erythrocytes (10): the low activity form carbonic anhydrase B, and the high activity form carbonic anhydrase C. Carbonic anhydrase B is found in greater quantity than carbonic anhydrase C. The complete amino-acid sequences of the two isozymes have been established (11)(12)(13)(14) and show a great deal of homology. The three-dimensional structure of carbonic anhydrase C has been established to 2-A resolution (15, 16); the present article presents the high-resolution structure determination of carbonic anhydrase B. MATERIALS AND METHODSCrystallization and Heavy Atom Derivatives. Human carbonic anhydrase B was isolated from erythrocytes (kindly provided by the University Hospital, Uppsala) by mild methods (17). The enzyme was further purified by electrophoresis and on a Sulfur-ethylsephadex C-50 ion exchange column. Crystals of the native enzyme were prepared from 2.3 M ammonium sulfate, pH 8.7, by a seeding technique in small, thick-walled glass capillaries as described (18). Heavy atom derivatives were prepared by soaking native enzyme crystals for at least a week in 2.3 M ammonium sulfate solution, pH 8.7, containing 1 mM heavy atom salts, K2Au(CN)2, * This is paper II in a series. In all 30 layers, zero and upper levels were collected to cover about 85% of the reflections within the 2-A sphere. Intensity measurements were performed by a fully automatic microdensitometer constructed by Ing. V. Klimecki of the Department of Chemistry, University of Uppsala, in collaboration with our group. The program system used for data processing was developed by one. of us (K.K.K.) and is similar to that described by Jarup et al. (21).All the symmetry-related reflections were averaged, and the average amplitudes were used in subsequent calculations. The reflections in the 10-A sphere and reflections below a threshold were omitted.. Out of the 14,000 unique reflections thus measured, about 10,500 reflections were used in the refinements of heavy atom parameters, phase angle calculations, and electron density maps.Heavy Atom Parameters and Phase Angle Calculation. The heavy atom positional parameters were initially determined from difference Patterson and difference Fourier calculations in two orthogonal projections. A single site mercury derivative (18) was used in the two centrosymmetric projections to calculate the signs used in the difference Fouriers from which the principal heavy atom positions were determined for the other derivatives. Subsequent cycles of least-squares refinement and difference Fouriers included all the derivatives. This procedure did not introduce any serious biasing effect due to the heavy atom derivatives concerned. Threedimensional difference Patterson and correlation functions (22) were calculated to verify the correct assignment of the heavy atom positions. Alternate cycles of phase angle calculation and least-squares refinement were performed for relative scale factor, overall isotropic temperature factor, positional paramet...

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Structure of human carbonic anhydrase B

Cited by 26 publications

References 7 publications

Interactions between carbonic anhydrase and its inhibitors revealed by gel electrophoresis and circular dichroism

Interactions between carbonic anhydrase and its inhibitors revealed by gel electrophoresis and circular dichroism

Carbonic Anhydrase as a Model for Biophysical and Physical-Organic Studies of Proteins and Protein−Ligand Binding

Crystal structure of human erythrocyte carbonic anhydrase B. Three-dimensional structure at a nominal 2.2-A resolution.

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