Glutathione is an organic compound with the chemical formula HOCOCH(NH2)CH2CH2CONHCH(CH2SH)CONHCH2COOH. It is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by sources such as reactive oxygen species, free radicals, peroxides, lipid peroxides, and heavy metals. It is a tripeptide with a gamma peptide linkage between the carboxyl group of the glutamate side chain and cysteine. The carboxyl group of the cysteine residue is attached by normal peptide linkage to glycine.
Peroxidases or peroxide reductases are a large group of enzymes which play a role in various biological processes. They are named after the fact that they commonly break up peroxides, and should not be confused with other enzymes that produce peroxide, which are often oxidases.
Trypanosomatida is a group of kinetoplastid unicellular organisms distinguished by having only a single flagellum. The name is derived from the Greek trypano (borer) and soma (body) because of the corkscrew-like motion of some trypanosomatid species. All members are exclusively parasitic, found primarily in insects. A few genera have life-cycles involving a secondary host, which may be a vertebrate, invertebrate or plant. These include several species that cause major diseases in humans. Some trypanosomatida are intracellular parasites, with the important exception of Trypanosoma brucei.
Kinetoplastida is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of a distinctive organelle called the kinetoplast, a granule containing a large mass of DNA. The group includes a number of parasites responsible for serious diseases in humans and other animals, as well as various forms found in soil and aquatic environments. The organisms are commonly referred to as "kinetoplastids" or "kinetoplasts".
Entamoeba coli is a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract. E. coli is important in medicine because it can be confused during microscopic examination of stained stool specimens with the pathogenic Entamoeba histolytica. This amoeba does not move much by the use of its pseudopod, and creates a "sur place (non-progressive) movement" inside the large intestine. Usually, the amoeba is immobile, and keeps its round shape. This amoeba, in its trophozoite stage, is only visible in fresh, unfixed stool specimens. Sometimes the Entamoeba coli have parasites as well. One is the fungus Sphaerita spp. This fungus lives in the cytoplasm of the E. coli. While this differentiation is typically done by visual examination of the parasitic cysts via light microscopy, new methods using molecular biology techniques have been developed. The scientific name of the amoeba, E. coli, is often mistaken for the bacterium, Escherichia coli. Unlike the bacterium, the amoeba is mostly harmless, and does not cause as many intestinal problems as some strains of the E. coli bacterium. To make the naming of these organisms less confusing, "alternate contractions" are used to name the species for the purpose making the naming easier; for example, using Esch. coli and Ent. coli for the bacterium and amoeba, instead of using E. coli for both.
Diphosphate—fructose-6-phosphate 1-phosphotransferase also known as PFP is an enzyme of carbohydrate metabolism in plants and some bacteria. The enzyme catalyses the reversible interconversion of fructose 6-phosphate and fructose 1,6-bisphosphate using inorganic pyrophosphate as the phosphoryl donor:
Melarsoprol is an arsenic-containing medication used for the treatment of sleeping sickness. It is specifically used for second-stage disease caused by Trypanosoma brucei rhodesiense when the central nervous system is involved. For Trypanosoma brucei gambiense, eflornithine or fexinidazole is usually preferred. It is effective in about 95% of people. It is given by injection into a vein.
The pentose phosphate pathway is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides. While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes). The reactions of the pathway were elucidated in the early 1950s by Bernard Horecker and co-workers.
Glutathione reductase (GR) also known as glutathione-disulfide reductase (GSR) is an enzyme that in humans is encoded by the GSR gene. Glutathione reductase catalyzes the reduction of glutathione disulfide (GSSG) to the sulfhydryl form glutathione (GSH), which is a critical molecule in resisting oxidative stress and maintaining the reducing environment of the cell. Glutathione reductase functions as dimeric disulfide oxidoreductase and utilizes an FAD prosthetic group and NADPH to reduce one molar equivalent of GSSG to two molar equivalents of GSH:
The glycosome is a membrane-enclosed organelle that contains the glycolytic enzymes. The term was first used by Scott and Still in 1968 after they realized that the glycogen in the cell was not static but rather a dynamic molecule. It is found in a few species of protozoa including the Kinetoplastida which include the suborders Trypanosomatida and Bodonina, most notably in the human pathogenic trypanosomes, which can cause sleeping sickness, Chagas's disease, and leishmaniasis. The organelle is bounded by a single membrane and contains a dense proteinaceous matrix. It is believed to have evolved from the peroxisome. This has been verified by work done on Leishmania genetics.
Alan Hutchinson Fairlamb, CBE, FRSE, FLS, FMedSci, FRSB is a Wellcome Trust Principal Research Fellow and Professor of Biochemistry in the Division of Biological Chemistry and Drug Discovery at the School of Life Sciences, University of Dundee, Scotland. From 2006-2011 he was a member of the Scientific and Technical Advisory Committee of the Special Programme for Research and Training in Tropical Diseases (TDR) -- an independent global programme of scientific collaboration co-sponsored by UNICEF, UNDP, the World Bank and WHO. Currently he is a member of the governing board of the Tres Cantos Open Lab Foundation, whose aim is to accelerate the discovery and development of medicines to tackle diseases of the developing world in an open collaborative manner.
In enzymology, a carbonyl reductase (NADPH) (EC 1.1.1.184) is an enzyme that catalyzes the chemical reaction
In enzymology, a CoA-glutathione reductase (EC 1.8.1.10) is an enzyme that catalyzes the chemical reaction
In enzymology, a pteridine reductase (EC 1.5.1.33) is an enzyme that catalyzes the chemical reaction
In enzymology, a trypanothione-disulfide reductase (EC 1.8.1.12) is an enzyme that catalyzes the chemical reaction
The enzyme methionine γ-lyase (EC 4.4.1.11, MGL) is in the γ-family of PLP-dependent enzymes. It degrades sulfur-containing amino acids to α-keto acids, ammonia, and thiols:
In enzymology, a glutathionylspermidine synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a trypanothione synthase (EC 6.3.1.9) is an enzyme that catalyzes the chemical reaction
The ascorbate-glutathione cycle, sometimes Foyer-Halliwell-Asada pathway, is a metabolic pathway that detoxifies hydrogen peroxide (H2O2), a reactive oxygen species that is produced as a waste product in metabolism. The cycle involves the antioxidant metabolites: ascorbate, glutathione and NADPH and the enzymes linking these metabolites.
Oxidation response is stimulated by a disturbance in the balance between the production of reactive oxygen species and antioxidant responses, known as oxidative stress. Active species of oxygen naturally occur in aerobic cells and have both intracellular and extracellular sources. These species, if not controlled, damage all components of the cell, including proteins, lipids and DNA. Hence cells need to maintain a strong defense against the damage. The following table gives an idea of the antioxidant defense system in bacterial system.
