Probing the role of Val228 on the catalytic activity of Scytalidium catalase

Göç, Günce; Balci, Sinem; Yorke, Briony A.; Pearson, Arwen R.; Karakuş, Yonca Yüzügüllü

doi:10.1016/j.bbapap.2021.140662

Cited by 3 publications

(7 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most interesting result was that the E484A, E484I, T188D, T188F and T188I variants were still catalytically active and possessed higher phenol oxidase activities than wild-type CATPO, although they were associated with heme b rather than heme d as in the wild-type enzyme. An increase in phenol oxidase activity in some heme b-containing variants upon the mutation of catalytically nonessential residues has previously been reported (Goc et al, 2021). Further kinetic analysis of the phenol oxidase activity also confirmed previous reports that this catalase enzyme can utilize a wide range of oxidase substrates (O ¨gel et al, 2006;Sutay Kocabas et al, 2008).…”

Section: Discussionsupporting

confidence: 87%

“…In addition, previous reports have shown that H 2 O 2 must be retained in the active pocket for the second step of the catalytic reaction (Domı ´nguez et al, 2010;Jha et al, 2012;Sevinc et al, 1999). Related to this, the conversion of Val228 in CATPO and Ile274 in HPII to smaller amino acids resulted in lower activity, consistent with the retention of H 2 O 2 in the heme cavity (Goc et al, 2021;Jha et al, 2012).…”

Section: Structural Characterization Of Glu484 and Thr188 Variantssupporting

confidence: 59%

“…The CATPO variants with increased phenol oxidase turnover all contain heme b (with two carboxyl chains in its structure) rather than heme d (with one carboxyl chain and one cis-hydroxyspirolactone in its structure). In our previous report, it was also shown that phenol oxidase activity is increased in heme-b-containing lateral channel variants (Goc et al, 2021).…”

Section: Catalase Activity †mentioning

confidence: 76%

“…They exhibit an unusual resistance to thermal degradation, denaturants such as detergents, organic solvents and salts, and proteolytic cleavage (Chelikani et al, 2004). A slightly larger number of crystal structures have been published for clade 2 enzymes, including 12 from variants of Scytalidium thermophilum catalase (also known as catalasephenol oxidase or CATPO; Yuzugullu, Trinh, Fairhurst et al, 2013;Yuzugullu, Trinh, Smith et al, 2013;Yuzugullu Karakus et al, 2018;Goc et al, 2021), than for clade 1 enzymes (Dı ´az et al, 2012). It has been shown that clade 2 enzymes predominantly possess heme d, which is a cis-hydroxyspirolactone and an oxidized derivative of heme b (Dı ´az et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Investigation of how gate residues in the main channel affect the catalytic activity of Scytalidium thermophilum catalase

Yuzugullu Karakus,

Goc,

Zengin Karatas

et al. 2024

Acta Cryst Sect D Struct Biol

Self Cite

View full text Add to dashboard Cite

Catalase is an antioxidant enzyme that breaks down hydrogen peroxide (H2O2) into molecular oxygen and water. In all monofunctional catalases the pathway that H2O2 takes to the catalytic centre is via the `main channel'. However, the structure of this channel differs in large-subunit and small-subunit catalases. In large-subunit catalases the channel is 15 Å longer and consists of two distinct parts, including a hydrophobic lower region near the heme and a hydrophilic upper region where multiple H2O2 routes are possible. Conserved glutamic acid and threonine residues are located near the intersection of these two regions. Mutations of these two residues in the Scytalidium thermophilum catalase had no significant effect on catalase activity. However, the secondary phenol oxidase activity was markedly altered, with k cat and k cat/K m values that were significantly increased in the five variants E484A, E484I, T188D, T188I and T188F. These variants also showed a lower affinity for inhibitors of oxidase activity than the wild-type enzyme and a higher affinity for phenolic substrates. Oxidation of heme b to heme d did not occur in most of the studied variants. Structural changes in solvent-chain integrity and channel architecture were also observed. In summary, modification of the main-channel gate glutamic acid and threonine residues has a greater influence on the secondary activity of the catalase enzyme, and the oxidation of heme b to heme d is predominantly inhibited by their conversion to aliphatic and aromatic residues.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Structural Characterization Of Glu484 and Thr188 Variantssupporting

confidence: 59%

Section: Catalase Activity †mentioning

confidence: 76%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of how gate residues in the main channel affect the catalytic activity of Scytalidium thermophilum catalase

Yuzugullu Karakus,

Goc,

Zengin Karatas

et al. 2024

Acta Cryst Sect D Struct Biol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Two other variants (I274G and I274C) are more difficult to interpret due to the peculiar features they present [ 59 ]. In the fungal L2 LSC CATPO, similar enzyme variants were obtained in the equivalent residue (Val228), but the heme orientations were not analyzed [ 60 ].…”

Section: Catalase Structures and Their Active Sitementioning

confidence: 99%

Monofunctional Heme-Catalases

Hansberg

2022

Antioxidants

View full text Add to dashboard Cite

The review focuses on four issues that are critical for the understanding of monofunctional catalases. How hydrogen peroxide (H2O2) reaches the active site and outcompetes water molecules to be able to function at a very high rate is one of the issues examined. Part of the answer is a gate valve system that is instrumental to drive out solvent molecules from the final section of the main channel. A second issue relates to how the enzyme deals with an unproductive reactive compound I (Cpd I) intermediate. Peroxidatic two and one electron donors and the transfer of electrons to the active site from NADPH and other compounds are reviewed. The new ascribed catalase reactions are revised, indicating possible measurement pitfalls. A third issue concerns the heme b to heme d oxidation, why this reaction occurs only in some large-size subunit catalases (LSCs), and the possible role of singlet oxygen in this and other modifications. The formation of a covalent bond between the proximal tyrosine with the vicinal residue is analyzed. The last issue refers to the origin and function of the additional C-terminal domain (TD) of LSCs. The TD has a molecular chaperone activity that is traced to a gene fusion between a Hsp31-type chaperone and a small-size subunit catalase (SSC).

show abstract

Electron Transfer

Leontieş

Aricov

Răducan

2023

Fundamental and Biomedical Aspects of Redox Processes

View full text Add to dashboard Cite

Oxidoreductases are a special class of enzymes that use the redox mechanism for the efficient transformation of organic substrates. Most oxidoreductases contain metals in the active site and, for optimal functioning, require the participation of a small co-substrate with the ability to donate electrons. From the multitude of enzymes with economic and applicable potential, the authors focused their attention on three particular classes: catalases, peroxidases, and laccases. Catalases and peroxidases contain heme iron in their active sites and most often require electron donors such as oxygen or hydrogen peroxide while laccase contains copper and demands special co-substrates such as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) or syringaldehyde. The theoretical aspects regarding the mechanism in which the electron transfer of the three enzymes is involved as well as the practical applications of the selected enzymes in the field of environmental remediation will be the subject of this chapter.

show abstract

Probing the role of Val228 on the catalytic activity of Scytalidium catalase

Cited by 3 publications

References 39 publications

Investigation of how gate residues in the main channel affect the catalytic activity of Scytalidium thermophilum catalase

Investigation of how gate residues in the main channel affect the catalytic activity of Scytalidium thermophilum catalase

Monofunctional Heme-Catalases

Electron Transfer

Contact Info

Product

Resources

About