Purification of a catalase-peroxidase from Halobacterium halobium: characterization of some unique properties of the halophilic enzyme

Abstract

A hydroperoxidase purified from the halophilic archaeon Halobacterium halobium exhibited both catalase and peroxidase activities, which were greatly diminished in a low-salt environment. Therefore, the purification was carried out in 2 M NaCi. Purified protein exhibited catalase activity over the narrow pH range of 6.0 to 7.5 and exhibited peroxidase activity between pH 6.5 and 8.0. Peroxidase activity was maximal at NaCi concentrations above 1 M, although catalase activity required 2 M NaCI for optimal function. Catalase activity was greatest at 50'C; at 90'C, the enzymatic activity was 20%o greater than at 250C. Peroxidase activity decreased rapidly above its maximum at 40'C. An activation energy of 2.5 kcal (ca. 10 kJ)/mol was calculated for catalase, and an activation energy of 4.0 kcal (ca. 17 kJ)/mol was calculated for peroxidase. Catalase activity was not inhibited by 3-amino-1,2,4-triazole but was inhibited by KCN and NaN3 (apparent KA [KAPP] of 50 and 67.5 FLM, respectively). Peroxidative activity was inhibited equally by KCN and NaN3 (K1APP for both, -30 tiM). The absorption spectrum showed a Soret peak at 404 nm, and there was no apparent reduction by dithionite. A heme content of 1.43 per tetramer was determined. The protein has a pI of 3.8 and an Mr of 240,000 and consists of four subunits of 60,300 each.

Purification and Characterization of an Iron Superoxide Dismutase and a Catalase from the Sulfate-Reducing Bacterium Desulfovibrio gigas

“…D. gigas SOD belongs to the former group of FeSODs, as indicated by the similarity in amino acid composition ( Lys 12 22 27 46 His 16 21 15 20 Arg 35 36 33 27 Asp 22 57 64 61 Thr 40 25 21 26 Ser 29 19 19 26 Glu 14 43 59 48 Pro 50 31 29 30 Gly 49 35 34 32 Ala 88 46 38 31 Cysteic acid 5 3 3 2 Val 34 28 21 33 Met 18 14 14 14 Ile 11 15 22 18 Leu 40 30 32 25 Tyr 18 17 19 25 Phe 18 26 28 31 Trp 9 9 8 The spectrum of the hemochrome complex of the D. gigas catalase indicates that it is a hemoprotein containing a protoheme IX moiety. A heme/subunit ratio of 1:2 has been found in some bacterial catalases (7,12,45). Our data show that D. gigas catalase has a 1:3 heme/subunit ratio.…”

Purification and Characterization of an Intracellular Catalase‐Peroxidase from Penicillium Simplicissimum

“…Besides their different catalytic behaviour these enzymes also differ in their reduction by dithionite, the narrow pH range for maximal activity, inactivation by hydrogen peroxide and their insensitivity to %amino-1,2,4-triazole. Most of the catalase-peroxidases are tetramers isolated from bacteria (Claiborne and Fridovich, 1979 ;Nadler et al, 1986;Hochman and Goldberg, 1991 ;Yumoto et al, 1990;Morris et al, 1992;Brown-Peterson and Salin, 1993). Those of B L K~~U S stearothermophi1u.s (Loprasert et al, 1988), Comamon c i~ cwizprunsoris (Nies and Schlegel,1 982), Mycobactevium tuIx~rcdosis (Diaz and Wayne, 1974) and Streptomyces cyaneus (Mliki and Zimmermann, 1992) exist as dimers.…”

Unique Presence of a Manganese Catalase in a Hyperthermophilic Archaeon, Pyrobaculum calidifontis VA1

“…(11,12,14,41,42), but there have been no previous reports of a manganese catalase. Recently, an abundant number of complete genome sequences from various archaeal strains have been determined.…”

“…A catalase-peroxidase and a monofunctional catalase were purified from the halophilic archaeon Halobacterium halobium (11,12), and a catalase-peroxidase was also purified…”

“…A catalase-peroxidase and a monofunctional catalase were purified from the halophilic archaeon Halobacterium halobium (11,12), and a catalase-peroxidase was also purified from Haloarcula marismortui (14). In methanogenic archaea, monofunctional catalases were purified from Methanosarcina barkeri (41) and Methanobrevibacter arboriphilus (42).…”