Related Research Articles
Post-translational modification (PTM) is the covalent and generally enzymatic modification of proteins following protein biosynthesis. This process occurs in the endoplasmic reticulum and the golgi apparatus. Proteins are synthesized by ribosomes translating mRNA into polypeptide chains, which may then undergo PTM to form the mature protein product. PTMs are important components in cell signaling, as for example when prohormones are converted to hormones.
Proteinogenic amino acids are amino acids that are incorporated biosynthetically into proteins during translation. The word "proteinogenic" means "protein creating". Throughout known life, there are 22 genetically encoded (proteinogenic) amino acids, 20 in the standard genetic code and an additional 2 that can be incorporated by special translation mechanisms.
The C-terminus is the end of an amino acid chain, terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus.
Transglutaminases are enzymes that in nature primarily catalyze the formation of an isopeptide bond between γ-carboxamide groups ( -(C=O)NH2 ) of glutamine residue side chains and the ε-amino groups ( -NH2 ) of lysine residue side chains with subsequent release of ammonia ( NH3 ). Lysine and glutamine residues must be bound to a peptide or a protein so that this cross-linking (between separate molecules) or intramolecular (within the same molecule) reaction can happen. Bonds formed by transglutaminase exhibit high resistance to proteolytic degradation (proteolysis). The reaction is
Dendrotoxins are a class of presynaptic neurotoxins produced by mamba snakes (Dendroaspis) that block particular subtypes of voltage-gated potassium channels in neurons, thereby enhancing the release of acetylcholine at neuromuscular junctions. Because of their high potency and selectivity for potassium channels, dendrotoxins have proven to be extremely useful as pharmacological tools for studying the structure and function of these ion channel proteins.
SV40 large T antigen is a hexamer protein that is a dominant-acting oncoprotein derived from the polyomavirus SV40. TAg is capable of inducing malignant transformation of a variety of cell types. The transforming activity of TAg is due in large part to its perturbation of the retinoblastoma (pRb) and p53 tumor suppressor proteins. In addition, TAg binds to several other cellular factors, including the transcriptional co-activators p300 and CBP, which may contribute to its transformation function.
Leupeptin, also known as N-acetyl-L-leucyl-L-leucyl-L-argininal, is a naturally occurring protease inhibitor that can inhibit cysteine, serine and threonine peptidases.
Slotoxin is a peptide from Centruroides noxius Hoffmann scorpion venom. It belongs to the short scorpion toxin superfamily.
Agitoxin is a toxin found in the venom of the scorpion Leiurus quinquestriatus hebraeus. Other toxins found in this species include charybdotoxin (CTX). CTX is a close homologue of Agitoxin.
Tyrosine aminotransferase is an enzyme present in the liver and catalyzes the conversion of tyrosine to 4-hydroxyphenylpyruvate.
The genus Lysobacter belongs to the family Xanthomonadaceae within the Gammaproteobacteria and includes at least 46 named species, including: Lysobacter enzymogenes, L. antibioticus, L. gummosus, L. brunescens, L. defluvii, L. niabensis, L. niastensis, L. daejeonensis, L. yangpyeongensis, L. koreensis, L. concretionis, L. spongiicola, and L. capsici. Lysobacter spp. were originally grouped with myxobacteria because they shared the distinctive trait of gliding motility, but they uniquely display a number of traits that distinguish them from other taxonomically and ecologically related microbes including high genomic G+C content and the lack of flagella. The feature of gliding motility alone has piqued the interest of many, since the role of gliding bacteria in soil ecology is poorly understood. In addition, while a number of different mechanisms have been proposed for gliding motility among a wide range of bacterial species, the genetic mechanism in Lysobacter remains unknown. Members of the Lysobacter group have gained broad interest for production of extracellular enzymes. The group is also regarded as a rich source for production of novel antibiotics, such as β-lactams containing substituted side chains, macrocyclic lactams and macrocyclic peptide or depsipeptide antibiotics like the katanosins.
Kexin is a prohormone-processing protease, specifically a yeast serine peptidase, found in the budding yeast. It catalyzes the cleavage of -Lys-Arg- and -Arg-Arg- bonds to process yeast alpha-factor pheromone and killer toxin precursors. The human homolog is PCSK4. It is a family of subtilisin-like peptidases. Even though there are a few prokaryote kexin-like peptidases, all kexins are eukaryotes. The enzyme is encoded by the yeast gene KEX2, and usually referred to in the scientific community as Kex2p. It shares structural similarities with the bacterial protease subtilisin. The first mammalian homologue of this protein to be identified was furin. In the mammal, kexin-like peptidases function in creating and regulating many differing proproteins.
Peptidoglycan glycosyltransferase is an enzyme used in the biosynthesis of peptidoglycan. It transfers a disaccharide-peptide from a donor substrate to synthesize a glycan chain.
Ubiquitin-conjugating enzyme E2 variant 2 is a protein that in humans is encoded by the UBE2V2 gene. Ubiquitin-conjugating enzyme E2 variant proteins constitute a distinct subfamily within the E2 protein family.
Lys-N is a metalloendopeptidase found in the mushroom Grifola frondosa that cleaves proteins on the amino side of lysine residues.
Lysyl endopeptidase is an enzyme. This enzyme catalyses the following chemical reaction
Beta-lytic metalloendopeptidase is an enzyme. This enzyme catalyses the following chemical reaction
Peptidyl-Asp metalloendopeptidase is an enzyme. This enzyme catalyses the following chemical reaction
Lysine Exporters are a superfamily of transmembrane proteins which export amino acids, lipids and heavy metal ions. They provide ionic homeostasis, play a role in cell envelope assembly, and protect from excessive concentrations of heavy metals in cytoplasm. The superfamily was named based on the early discovery of the LysE carrier protein of Corynebacterium glutamicum.
Dihydromaltophilin, or heat stable anti-fungal factor (HSAF), is a secondary metabolite of Streptomyces sp. and Lysobacter enzymogenes. HSAF is a polycyclic tetramate lactam containing a single tetramic acid unit and a 5,5,6-tricyclic system. HSAF has been shown to have anti-fungal activity mediated through the disruption of the biosynthesis of Sphingolipid's by targeting a ceramide synthase unique to fungi.
References
- ↑ Jekel, PA; Weijer, WJ; Beintema, JJ (15 October 1983). "Use of endoproteinase Lys-C from Lysobacter enzymogenes in protein sequence analysis". Analytical Biochemistry. 134 (2): 347–54. doi:10.1016/0003-2697(83)90308-1. PMID 6359954.
- ↑ Shah, Haroun N.; Gharbia, Saheer E. (2010). Mass Spectrometry for Microbial Proteomics. Chichester, UK: Wiley. p. 136. ISBN 9781119991922.
- ↑ "Catalog".
§gtfgf
 | This enzyme-related article is a stub. You can help Wikipedia by expanding it. |