A new human catalytic antibody Se‐scFv‐2D8 and its selenium‐containing single domains with high GPX activity

Xu, Junjie; Song, Jian; Su, Jiaming; Wei, Jingyan; Yu, Yang; Lv, Shaowu; Li, Wei; Nie, Guangjun

doi:10.1002/jmr.1001

Cited by 6 publications

(3 citation statements)

References 46 publications

(56 reference statements)

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“…Typical host systems include cyclodextrins, catalytic antibodies, and natural enzymes [6][7][8]. Cyclodextrins (CDs) are well known, naturally-occurring, cyclic oligosaccharides composed of at least six α-1-4-linked α-D-glucopyranoside units.…”

Section: Introductionmentioning

confidence: 99%

Study of 8 Types of Glutathione Peroxidase Mimics Based on β-Cyclodextrin

Wang¹,

Qu²,

Xie³

et al. 2017

Catalysts

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Glutathione peroxidase is key for the removal of H 2 O 2 and other hydroperoxides and therefore, it has an important role in the maintenance of the reactive oxygen species (ROS) metabolic balance in vivo. The native enzymes of the glutathione peroxidase family (GPx) have many defects, such as instability in vitro and poor availability. GPx mimetics has become a topic of considerable interest in artificial enzyme research. Many forms of GPx mimics have been synthesized, by including selenium and tellurium (double-bridged and single-bridged, 2-substituted and 6-substituted) in a mother molecule but differences the GPx mimics enzymatic activity have rarely been compared. We designed and synthesized eight cyclodextrin derivatives and used two types of enzyme assays to determine their activities. The results show that: (a) tellurium-containing GPx mimics have higher activity than that of selenium-containing GPx mimics; (b) dual-bridged mimics have higher activity than bis-bridged mimics; and (c) 2-position modified cyclodextrin has higher activity than 6-position modified cyclodextrin.

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Section: Introductionmentioning

confidence: 99%

Study of 8 Types of Glutathione Peroxidase Mimics Based on β-Cyclodextrin

Wang¹,

Qu²,

Xie³

et al. 2017

Catalysts

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“…Glutathione S ‐transferase (GST) and glutaredoxin (Grx) are natural protein scaffolds with intrinsic GSH‐binding sites and widely used to redesign GPx mimics . Furthermore, a number of GPx mimics have been built by a monoclonal antibody and bioimprinting techniques, which introduce the GSH binding site into the models .…”

Section: Introductionmentioning

confidence: 99%

Heterologous expression and characterization of human cellular glutathione peroxidase mutants

Guo

Liu

et al. 2014

IUBMB Life

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Cellular glutathione peroxidase (GPx1; EC1.11.1.9) is a major intracellular antioxidant selenoenzyme in mammals. However, the complicated expression mechanism of selenocysteine (Sec)-containing protein increases the difficulty of expressing human GPx1 (hGPx1) in Escherichia coli (E. coli). In this study, hGPx1 gene was cloned from a cDNA library of the human hepatoma cell line HepG2. The codon UGA encoding Sec49 of hGPx1 was first mutated to UGC encoding cysteine (Cys) and then biosynthetically converted to Sec during expression in an E. coli BL21(DE3)cys auxotrophic system. Seleno-GPx1Sec displayed a low GPx activity of 522 U/lmol. To improve the activity, the other five Cys residues (C2, C78, C115, C156, C202)were mutated to serine (Ser) in one hGPx1 molecule. The mutant seleno-hGPx1 Ser showed a high activity of 5278 U/ lmol, which was more than 10-fold enhanced as compared with seleno-GPx1 Sec . The activity was the highest among all of those seleno-proteins obtained by this method so far. Kinetic analysis of seleno-hGPx1 Ser showed a typical ping-pong mechanism, which was similar to those of natural GPxs. This research will be of value in overcoming the problem of limited sources of natural GPx and substantially promotes the research of the characterization of GPx.

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“…And the fact that the mechanism of Sec incorporation differs from prokaryotes to eukaryotes makes it difficult to directly heterologously express recombinant mammalian selenoproteins in E. coli (8). It has been reported that several GPX mimics with high activity are produced by eukaryotic expression system and chemical method (9)(10)(11)(12)(13). However, the restrictions, such as low yield and short of specificity, make it inappropriate to produce quantities of selenoproteins and predict the structure of the protein scaffold introduced Sec for imitating GPX.…”

Section: Introductionmentioning

confidence: 99%

Characterization of catalytic activity and structure of selenocysteine‐containing hGSTZ1c‐1c based on site‐directed mutagenesis and computational analysis

Song

et al. 2013

IUBMB Life

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Human glutathione transferase zeta 1c-1c (hGSTZ1c-1c) is one of the glutathione transferase isoenzymes and considered to be a protein scaffold to imitate glutathione peroxidase (GPX) owing to the natural binding site of glutathione (GSH). In this report, several residues near GSH were mutated to selenocysteine (Sec) or cysteine (Cys) residues and the impacts of the substitutions on different activities were discussed. Mutations of Ser-14 or/and Ser-15 to Cys or Sec residues resulted in dramatic loss of catalytic activity of hGSTZ1c-1c with chlorofluoroacetic acid as substrate, which indicated the importance of the hydroxyl groups in Ser-14 and Ser-15. And subsequent study by molecular modeling suggested that Ser-15 was probably involved in catalysis, while Ser-14 may play a crucial role in binding and orientation of GSH and possibly had a synergistic effect with Ser-15 in catalysis. On the contrary, the result of converting Cys-16 to Ser indicated its trivial role in catalysis. The investigations of the selenocysteine-containing hGSTZ1c-1c (seleno-hGSTZ1c-1c) and the mutant S17C implied that the substitutions of multi-Sec for Cys residues at position 16, 137, and 205 could lead to subtle change in the structure of the protein molecule and concomitant change in catalytic activity as a direct result. This finding provides overwhelming evidence that the protein scaffold containing fewer cysteines should be chosen for imitating GPX using cysteine auxotrophic strain system to avoid unexpected structural changes.

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A new human catalytic antibody Se‐scFv‐2D8 and its selenium‐containing single domains with high GPX activity

Cited by 6 publications

References 46 publications

Study of 8 Types of Glutathione Peroxidase Mimics Based on β-Cyclodextrin

Study of 8 Types of Glutathione Peroxidase Mimics Based on β-Cyclodextrin

Heterologous expression and characterization of human cellular glutathione peroxidase mutants

Characterization of catalytic activity and structure of selenocysteine‐containing hGSTZ1c‐1c based on site‐directed mutagenesis and computational analysis

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