Chemicals & Small Molecules

NAD Kinase (NADK) is an enzyme that belongs to the NAD Kinase family. It is a widely expressed enzyme, but it is not detected in skeletal muscle. NADK converts Nicotinamide Adenine Dinucleotide (NAD+) into NADP+, through phosphorylating the NAD+ coenzyme. NADP+ is an essential coenzyme in metabolism and provides reducing power to biosynthetic processes such as fatty acid biosynthesis. The structure of the NADK from the archaean Archaeoglobus fulgidus has been determined.

Spondin-2, also referred to as mindin, belongs to the F-spondin family of secreted extracellular matrix proteins. Spondins are characterised by the presence of F-spondin domains 1 and 2 (FS1 and FS2) at the N-terminus and a thrombospondin-type 1 repeat (TSR1) domain at the C-terminus. Spondin-2 functions as a pattern-recognition molecule for bacterial and viral pathogens and as an integrin ligand for inflammatory cell recruitment and T cell priming. In addition to its roles in promoting neuron outgrowth and inhibiting both cancer and angiogenesis, Spondin-2 plays an important role in the initiation of the immune response and is involved in inflammatory processes.

Kallikreins are a subgroup of Serine Proteases having diverse physiological functions. Growing evidence suggests that many Kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers. This gene is one of the fifteen Kallikrein subfamily members located in a cluster on chromosome 19. Its encoded protein is secreted and may play a role in suppression of tumorigenesis in breast and prostate cancers. Alternate splicing of this gene results in multiple transcript variants encoding the same protein.

Nicotinate-Nucleotide Pyrophosphorylase (QPRT) belongs to the nadC/modD family. QPRT plays an improtant role in catabolism of quinolinate which acts as a potent endogenous exitotoxin to neurons. In addition, QPRT serves as an an intermediate in the Tryptophan-Nicotinamide Adenine Dinucleotide pathway. QPRT participates in some pathways including Cofactor biosynthesis, NAD(+) biosynthesis and the Nicotinate D-Ribonucleotide from Quinolinate. In addition, QPRT is involved in the catabolism of Quinolinic Acid (QA). The activity toward QA is slightly repressed by phosphoribosylpyrophosphate (PRPP) in both a competitive and a non-competitive manner.

Kallikrein-1 (KLK1) is a member of human tissue Kallikrein family. Human KLK1 precursor contains a singal peptide (residues 1 to 18), a short pro peptide (residues 19 to 24) and a mature chain (residues 25 to 262). The function of KLK1 is to cleave Kininogen in order to release the vasoactive Kinin peptide (Lysyl-Bradykinin or Bradykinin). The Kinin peptide controls blood pressure reduction, vasodilation, smooth muscle relaxation and contraction, pain induction and inflammation. KLK1 also plays a role in angiogensis and tumorigenesis.

Ketohexokinase, also known as Hepatic fructokinase, is a member of the carbohydrate kinase PfkB family. It exits as a homodimer and most abundant in liver, kidney, gut, spleen and pancreas. Low levels also found in adrenal, muscle, brain and eye.This enzyme catalyzes conversion of fructose to fructose-1-phosphate. It is the first enzyme with a specialized pathway that catabolizes dietary fructose. Defects in KHK are the cause of fructosuria.

Serum Amyloid A1 Protein (SAA1) is an acute phase apolipoprotein reactant that is produced predominantly by hepatocytes and is under the regulation of inflammatory cytokines. SAA is produced mainly in the liver and circulates in low levels in the blood. SAA may play a role in the immune system and facilitate the repair of injured tissues, it also acts as an antibacterial agent, and signals the migration of germ-fighting cells to sites of infection. SAA also functions as an apolipoprotein of the HDL complex. The SAA cleavage product designated amyloid protein A is deposited systemically as amyloid in vital organs such as the liver, spleen, and kidneys in chronic inflammatory diseases patients. These deposits are extremely insoluble and resistant to proteolysis; they disrupt tissue structure and compromise performance.

Semenogelin-1 (SEMG1) is the predominant protein in semen; it is a secretory protein involved in the formation of a gel matrix entrapping the accessory gland secretions and ejaculated spermatozoa. The prostate-specific antigen (PSA) protease processes SEMG1 into smaller peptides, each possibly having a separate function. In the proteolysis process, Alpha-inhibin-92 and alpha-inhibin-31 are produced; they inhibit the secretion of pituitary follicle-stimulating hormone. At the same time, it breaks down the gel matrix, allowing the spermatozoa to move more freely.

DNA Fragmentation Factor Subunit Alpha (DFFA). DFFA exists as a heterodimer (DFF) with DFFB. DFF is activated once DFFA is cleaved by Caspase-3. The cleaved fragments of DFFA detach from DFFB (the active component of DFF), which in turn triggers DNA fragmentation as well as chromatin condensation during apoptosis. A reduced level of DFFA detected in ovarian endometriosis may be a part of an apoptosis-resistant mechanism enhancing the disease progression.