Structure of human erythrocyte catalase

Abstract

Catalase (E.C. 1.11.1.6) was purified from human erythrocytes and crystallized in three different forms: orthorhombic, hexagonal and tetragonal. The structure of the orthorhombic crystal form of human erythrocyte catalase (HEC), with space group P2(1)2(1)2(1) and unit-cell parameters a = 84.9, b = 141.7, c = 232.5 A, was determined and refined with 2.75 A resolution data. Non-crystallographic symmetry restraints were employed and the resulting R value and R(free) were 0.206 and 0.272, respectively. The overall structure and arrangement of HEC molecules in the orthorhombic unit cell were very similar to those of bovine liver catalase (BLC). However, no NADPH was observed in the HEC crystal and a water was bound to the active-site residue His75. Conserved lattice interactions suggested a common growth mechanism for the orthorhombic crystals of HEC and BLC.

Novel Insights into the Basis for Escherichia coli Superoxide Dismutase's Metal Ion Specificity from Mn-Substituted FeSOD and Its Very High Em

“…This may reflect the fact that superoxide dismutation includes two half-reactions, one oxidative and the other reductive, each of which would be spontaneous for one metal ion and the other of which may be imposed (at some cost to the first) by the protein. 3 SOD catalyzes the disproportionation of 2O 2…”

Discontinuous native protein gel electrophoresis

“…Catalase and GAPDH are virtually spherical tetramers [7,8], the 43 kDa ovalbumin is ellipsoid [9], and BSA is a heart-shaped protein [10]. Under nonreducing conditions, these globular proteins yield a consistent calibration curve (Fig.…”

“…1a), after preincubation under reducing conditions, PTB (lane 6) migrated faster than the 69 kDa BSA (lane 3), indicating that PTB is a monomer under reducing conditions like in the cell. The migration of two tetrameric proteins, the 230 kDa catalase (lane 1) and the 143 kDa glyceraldehyde-3-phosphate-dehydrogenase (GAPDH, GD) (lane 2) [7,8], demonstrate that this gel system preserves the noncovalent interactions between subunits of oligomeric proteins.…”

Hydroxyl Radical Generation Theory: A Possible Explanation of Unexplained Actions of Mammalian Catalase

“…The altered catalase activity has been observed in number of disease conditions [2][3][4]. The crystal structure of tetrameric human erythrocyte catalse (HEC) has been identified which was very similar to those of bovine liver catalase (BLC) [5,6] with functionally important amino acid sequences conserved [7].…”