In biochemistry, a kinase is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group. These two processes, phosphorylation and dephosphorylation, occur four times during glycolysis.
A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ or a flavin coenzyme such as FAD or FMN. Like all catalysts, they catalyze reverse as well as forward reactions, and in some cases this has physiological significance: for example, alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde in animals, but in yeast it catalyzes the production of ethanol from acetaldehyde.
Isomerases are a general class of enzymes that convert a molecule from one isomer to another. Isomerases facilitate intramolecular rearrangements in which bonds are broken and formed. The general form of such a reaction is as follows:
In biochemistry, flavin adenine dinucleotide (FAD) is a redox-active coenzyme associated with various proteins, which is involved with several enzymatic reactions in metabolism. A flavoprotein is a protein that contains a flavin group, which may be in the form of FAD or flavin mononucleotide (FMN). Many flavoproteins are known: components of the succinate dehydrogenase complex, α-ketoglutarate dehydrogenase, and a component of the pyruvate dehydrogenase complex.
Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin. These proteins are involved in a wide array of biological processes, including removal of radicals contributing to oxidative stress, photosynthesis, and DNA repair. The flavoproteins are some of the most-studied families of enzymes.
Novobiocin, also known as albamycin or cathomycin, is an aminocoumarin antibiotic that is produced by the actinomycete Streptomyces niveus, which has recently been identified as a subjective synonym for S. spheroides a member of the class Actinomycetia. Other aminocoumarin antibiotics include clorobiocin and coumermycin A1. Novobiocin was first reported in the mid-1950s.
Cyclopiazonic acid (α-CPA), a mycotoxin and a fungal neurotoxin, is made by the molds Aspergillus and Penicillium. It is an indole-tetramic acid that serves as a toxin due to its ability to inhibit calcium-dependent ATPases found in the endoplasmic and sarcoplasmic reticulum. This inhibition disrupts the muscle contraction-relaxation cycle and the calcium gradient that is maintained for proper cellular activity in cells.
Enzyme catalysis is the increase in the rate of a process by a biological molecule, an "enzyme". Most enzymes are proteins, and most such processes are chemical reactions. Within the enzyme, generally catalysis occurs at a localized site, called the active site.
Isopentenyl pyrophosphate isomerase, also known as Isopentenyl-diphosphate delta isomerase, is an isomerase that catalyzes the conversion of the relatively un-reactive isopentenyl pyrophosphate (IPP) to the more-reactive electrophile dimethylallyl pyrophosphate (DMAPP). This isomerization is a key step in the biosynthesis of isoprenoids through the mevalonate pathway and the MEP pathway.
Mannose-6 phosphate isomerase (MPI), alternately phosphomannose isomerase (PMI) is an enzyme which facilitates the interconversion of fructose 6-phosphate (F6P) and mannose-6-phosphate (M6P). Mannose-6-phosphate isomerase may also enable the synthesis of GDP-mannose in eukaryotic organisms. M6P can be converted to F6P by mannose-6-phosphate isomerase and subsequently utilized in several metabolic pathways including glycolysis and capsular polysaccharide biosynthesis. PMI is monomeric and metallodependent on zinc as a cofactor ligand. PMI is inhibited by erythrose 4-phosphate, mannitol 1-phosphate, and to a lesser extent, the alpha anomer of M6P.
Penitrem A (tremortin) is an indole-diterpenoid mycotoxin produced by certain species of Aspergillus, Claviceps, and Penicillium, which can be found growing on various plant species such as ryegrass. Penitrem A is one of many secondary metabolites following the synthesis of paxilline in Penicillium crostosum. Penitrem A poisoning in humans and animals usually occurs through the consumption of contaminated foods by mycotoxin-producing species, which is then distributed through the body by the bloodstream. It bypasses the blood-brain barrier to exert its toxicological effects on the central nervous system. In humans, penitrem A poisoning has been associated with severe tremors, hyperthermia, nausea/vomiting, diplopia, and bloody diarrhea. In animals, symptoms of penitrem A poisoning has been associated with symptoms ranging from tremors, seizures, and hyperthermia to ataxia and nystagmus.
Cystathionine beta-lyase, also commonly referred to as CBL or β-cystathionase, is an enzyme that primarily catalyzes the following α,β-elimination reaction
The enzyme chorismate synthase catalyzes the chemical reaction
In enzymology, a geranyltranstransferase is an enzyme that catalyzes the chemical reaction
Ergocryptine is an ergopeptine and one of the ergot alkaloids. It is isolated from ergot or fermentation broth and it serves as starting material for the production of bromocriptine.
Aucubin is an iridoid glycoside. Iridoids are commonly found in plants and function as defensive compounds. Iridoids decrease the growth rates of many generalist herbivores.
Morphinone reductase is an enzyme which catalyzes the NADH-dependent saturation of the carbon-carbon double bond of morphinone and codeinone, yielding hydromorphone and hydrocodone respectively. This saturation reaction is assisted by a FMN cofactor and the enzyme is a member of the α/β-barrel flavoprotein family. The sequence of the enzyme has been obtained from bacteria Pseudomonas putida M10 and has been successfully expressed in yeast and other bacterial species. The enzyme is reported to harbor high sequence and structural similarity to the Old Yellow Enzyme, a large group of flavin-dependent redox biocatalysts of yeast species, and an oestrogen-binding protein of Candida albicans. The enzyme has demonstrated value in biosynthesis of semi-opiate drugs in microorganisms, expanding the chemical diversity of BIA biosynthesis.
L-ornithine N5 monooxygenase (EC 1.14.13.195 or EC 1.14.13.196) is an enzyme which catalyzes one of the following chemical reactions:
L-ornithine + NADPH + O2 N(5)-hydroxy-L-ornithine + NADP+ + H2O L-ornithine + NAD(P)H + O2 N(5)-hydroxy-L-ornithine + NAD(P)+ + H2O
Prenylated flavin mononucleotide (prFMN) is a cofactor biosynthesized by the flavin prenyltransferase UbiX and used by UbiD enzymes for reversible decarboxylation reactions. Hence, prFMN is pivotal for catalysis in the ubiquitous microbial UbiD/X system.
Ferulic acid decarboxylases (Fdc) are decarboxylase enzymes capable of the reversible decarboxylation of aromatic carboxylic acids such as ferulic acid and cinnamic acid. Fdc's are fungal homologues of the E.coli UbiD enzyme which is involved in ubiquinone biosynthesis. This places Fdc within the wider UbiD enzyme family, representing a distinct clade within the family Presence of fdc1 and the associated pad1 genes were shown to be required for the decarboxylation of phenylacrylic acids in Saccharomyces cerevisiae.
