Vitamin C is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical "serum" ingredient to treat melasma and wrinkles on the face. It is used to prevent and treat scurvy. Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant. Most animals are able to synthesize their own vitamin C. However, apes and monkeys, most bats, some rodents, and certain other animals must acquire it from dietary sources.
Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated −NH+
3 form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain lysyl ((CH2)4NH2), classifying it as a basic, charged (at physiological pH), aliphatic amino acid. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both. For the purpose of this article, lysine will refer to the biologically active enantiomer L-lysine, where the α-carbon is in the S configuration.
Alcohol dehydrogenases (ADH) (EC 1.1.1.1) are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD+) to NADH. In humans and many other animals, they serve to break down alcohols that are otherwise toxic, and they also participate in the generation of useful aldehyde, ketone, or alcohol groups during the biosynthesis of various metabolites. In yeast, plants, and many bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD+.
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other, nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH (H for hydrogen), respectively.
Biological carbon fixation or сarbon assimilation is the process by which inorganic carbon is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use a process called chemosynthesis in the absence of sunlight.
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP+ or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require NADPH as a reducing agent ('hydrogen source'). NADPH is the reduced form of NADP+, the oxidized form. NADP+ is used by all forms of cellular life.
Malate dehydrogenase (EC 1.1.1.37) (MDH) is an enzyme that reversibly catalyzes the oxidation of malate to oxaloacetate using the reduction of NAD+ to NADH. This reaction is part of many metabolic pathways, including the citric acid cycle. Other malate dehydrogenases, which have other EC numbers and catalyze other reactions oxidizing malate, have qualified names like malate dehydrogenase (NADP+).
L-Gulonolactone oxidase is an enzyme that produces vitamin C, but is non-functional in Haplorrhini, in some bats, and in guinea pigs. It catalyzes the reaction of L-gulono-1,4-lactone with oxygen to form L-xylo-hex-3-gulonolactone (2-keto-gulono-γ-lactone) and hydrogen peroxide. It uses FAD as a cofactor. The L-xylo-hex-3-gulonolactone then converts to ascorbic acid spontaneously, without enzymatic action.
Ascorbate peroxidase (or L-ascorbate peroxidase, APX) (EC 1.11.1.11) is an enzyme that catalyzes the chemical reaction
UTP—glucose-1-phosphate uridylyltransferase also known as glucose-1-phosphate uridylyltransferase is an enzyme involved in carbohydrate metabolism. It synthesizes UDP-glucose from glucose-1-phosphate and UTP; i.e.,
In molecular biology, the protein domain Saccharopine dehydrogenase (SDH), also named Saccharopine reductase, is an enzyme involved in the metabolism of the amino acid lysine, via an intermediate substance called saccharopine. The Saccharopine dehydrogenase enzyme can be classified under EC 1.5.1.7, EC 1.5.1.8, EC 1.5.1.9, and EC 1.5.1.10. It has an important function in lysine metabolism and catalyses a reaction in the alpha-Aminoadipic acid pathway. This pathway is unique to fungal organisms therefore, this molecule could be useful in the search for new antibiotics. This protein family also includes saccharopine dehydrogenase and homospermidine synthase. It is found in prokaryotes, eukaryotes and archaea.
In enzymology, a homoserine dehydrogenase (EC 1.1.1.3) is an enzyme that catalyzes the chemical reaction
In enzymology, histidinol dehydrogenase (HIS4) (HDH) (EC 1.1.1.23) is an enzyme that catalyzes the chemical reaction
In enzymology, a mycothiol-dependent formaldehyde dehydrogenase (EC 1.1.1.306) is an enzyme that catalyzes the chemical reaction
The enzyme UDP-glucose 4-epimerase, also known as UDP-galactose 4-epimerase or GALE, is a homodimeric epimerase found in bacterial, fungal, plant, and mammalian cells. This enzyme performs the final step in the Leloir pathway of galactose metabolism, catalyzing the reversible conversion of UDP-galactose to UDP-glucose. GALE tightly binds nicotinamide adenine dinucleotide (NAD+), a co-factor required for catalytic activity.
Inosine-5′-monophosphate dehydrogenase (IMPDH) is a purine biosynthetic enzyme that catalyzes the nicotinamide adenine dinucleotide (NAD+)-dependent oxidation of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), the first committed and rate-limiting step towards the de novo biosynthesis of guanine nucleotides from IMP. IMPDH is a regulator of the intracellular guanine nucleotide pool, and is therefore important for DNA and RNA synthesis, signal transduction, energy transfer, glycoprotein synthesis, as well as other process that are involved in cellular proliferation.
In molecular biology, the ELFV dehydrogenase family of enzymes include glutamate, leucine, phenylalanine and valine dehydrogenases. These enzymes are structurally and functionally related. They contain a Gly-rich region containing a conserved Lys residue, which has been implicated in the catalytic activity, in each case a reversible oxidative deamination reaction.
Alcohol dehydrogenase (nicotinoprotein) (EC 1.1.99.36, NDMA-dependent alcohol dehydrogenase, nicotinoprotein alcohol dehydrogenase, np-ADH, ethanol:N,N-dimethyl-4-nitrosoaniline oxidoreductase) is an enzyme with systematic name ethanol:acceptor oxidoreductase. This enzyme catalyses the following chemical reaction
L-galactonolactone dehydrogenase (EC 1.3.2.3, galactonolactone dehydrogenase, L-galactono-gamma-lactone dehydrogenase, L-galactono-gamma-lactone:ferricytochrome-c oxidoreductase, GLDHase, GLDase) is an enzyme with systematic name L-galactono-1,4-lactone:ferricytochrome-c oxidoreductase. This enzyme catalyses the following chemical reaction
GDP-L-galactose phosphorylase is an enzyme with systematic name GDP:alpha-L-galactose 1-phosphate guanylyltransferase. This enzyme catalyses the following chemical reaction
