An oligopeptide, often just called peptide, consists of two to twenty amino acids and can include dipeptides, tripeptides, tetrapeptides, and pentapeptides. Some of the major classes of naturally occurring oligopeptides include aeruginosins, cyanopeptolins, microcystins, microviridins, microginins, anabaenopeptins, and cyclamides. Microcystins are best studied, because of their potential toxicity impact in drinking water. A review of some oligopeptides found that the largest class are the cyanopeptolins (40.1%), followed by microcystins (13.4%).
In biology and biochemistry, protease inhibitors, or antiproteases, are molecules that inhibit the function of proteases. Many naturally occurring protease inhibitors are proteins.
DD-transpeptidase is a bacterial enzyme that catalyzes the transfer of the R-L-αα-D-alanyl moiety of R-L-αα-D-alanyl-D-alanine carbonyl donors to the γ-OH of their active-site serine and from this to a final acceptor. It is involved in bacterial cell wall biosynthesis, namely, the transpeptidation that crosslinks the peptide side chains of peptidoglycan strands.
Viomycin is a member of the tuberactinomycin family, a group of nonribosomal peptide antibiotics exhibiting anti-tuberculosis activity. The tuberactinomycin family is an essential component in the drug cocktail currently used to fight infections of Mycobacterium tuberculosis. Viomycin was the first member of the tuberactinomycins to be isolated and identified, and was used to treat TB until it was replaced by the less toxic, but structurally related compound, capreomycin. The tuberactinomycins target bacterial ribosomes, binding RNA and disrupting bacterial protein synthesis and certain forms of RNA splicing. Viomycin is produced by the actinomycete Streptomyces puniceus.
N-Acetylaspartylglutamic acid is a peptide neurotransmitter and the third-most-prevalent neurotransmitter in the mammalian nervous system. NAAG consists of N-acetylaspartic acid (NAA) and glutamic acid coupled via a peptide bond.
Pepstatin is a potent inhibitor of aspartyl proteases. It is a hexa-peptide containing the unusual amino acid statine, having the sequence Isovaleryl-Val-Val-Sta-Ala-Sta (Iva-Val-Val-Sta-Ala-Sta). It was originally isolated from cultures of various species of Actinomyces due to its ability to inhibit pepsin at picomolar concentrations. It was later found to inhibit nearly all acid proteases with high potency and, as such, has become a valuable research tool, as well as a common constituent of protease inhibitor cocktails.
Aquayamycin is an anthraquinone derivative. It is an inhibitor of the enzyme tyrosine hydroxylase.
Ubenimex (INN), also known more commonly as bestatin, is a competitive, reversible protease inhibitor. It is an inhibitor of arginyl aminopeptidase (aminopeptidase B), leukotriene A4 hydrolase (a zinc metalloprotease that displays both epoxide hydrolase and aminopeptidase activities), alanyl aminopeptidase (aminopeptidase M/N), leucyl/cystinyl aminopeptidase (oxytocinase/vasopressinase), and membrane dipeptidase (leukotriene D4 hydrolase). It is being studied for use in the treatment of acute myelocytic leukemia and lymphedema. It is derived from Streptomyces olivoreticuli. Ubenimex has been found to inhibit the enzymatic degradation of oxytocin, vasopressin, enkephalins, and various other peptides and compounds.
Statine is a gamma amino acid that occurs twice in the sequence of pepstatin, a protease inhibitor that is active against pepsin and other acid proteases. It is thought to be responsible for the inhibitory activity of pepstatin because it mimics the tetrahedral transition state of peptide catalysis.
Albomycins are a group of naturally occurring antibiotics belonging to the class of sideromycins, which are "compounds composed of iron carriers called siderophores linked to antibiotic moieties". They are particularly effective against Gram-negative bacteria of the family Enterobacteriaceae and few Gram-positive bacteria such s Streptococcus pneumoniae, Bacillus subtilis and Staphylococcus aureus. In 2000 a group of scientists from SmithKline Beecham Pharmaceuticals, UK reported that the antibiotic part of albomycin in vitro can inhibit seryl-tRNA synthetase from both eukaryotic and prokaryotic representatives.
Neopluramycin is an antibiotic that inhibits nucleic acid synthesis. It has been isolated from the cultured broth of a strain of Streptomyces pluricolorescens as orange crystals, and analytical data and molecular weight determination are consistent with the empirical formula C
41H
50N
2O
10.
Streptomyces isolates have yielded the majority of human, animal, and agricultural antibiotics, as well as a number of fundamental chemotherapy medicines. Streptomyces is the largest antibiotic-producing genus of Actinomycetota, producing chemotherapy, antibacterial, antifungal, antiparasitic drugs, and immunosuppressants. Streptomyces isolates are typically initiated with the aerial hyphal formation from the mycelium.
Streptomyces amakusaensis is a bacterium species from the genus of Streptomyces which has been isolated from soil from the Amakusa Island in Japan. Streptomyces amakusaensis produces tuberin and nagstatin.
Streptomyces bikiniensis is a bacterium species from the genus Streptomyces which has isolated from soil from the island Bikini atoll. Streptomyces bikiniensis produces streptomycin II and carboxypeptidase.
Streptomyces coeruleorubidus is a bacterium species from the genus of Streptomyces which has been isolated from marine sediment. Streptomyces coeruleorubidus produces the following medications: pacidamycin 1, baumycin B1, baumycin B2, baumycin C1, feudomycin A, feudomycin B, feudomycin C, ficellomycin, feudomycinone A, and rubomycin.
Streptomyces griseoaurantiacus is a thermotolerant bacterium species from the genus of Streptomyces which was isolated from marine sediment. Streptomyces griseoaurantiacus produces the antibiotics manumycin, diperamycin and chinikomycin, and griseolic acid.
Streptomyces halstedii is a bacterium species from the genus of Streptomyces which has been isolated from deeper soil layers. Streptomyces halstedii produces magnamycin B, vicenistatin deltamycin A2, deltamycin A3, bafilomycin B1 and bafilomycin C1. Streptomyces halstedii also produces complex antifungal antibiotics like oligomycins and the antibiotics anisomycin and sinefungin.
Streptomyces lavendofoliae is a bacterium species from the genus of Streptomyces which has been isolated from soil in Russia. Streptomyces lavendofoliae produces fosfazinomycin A, fosfazinomycin B and piperastatin B
Streptomyces nitrosporeus is a bacterium species from the genus of Streptomyces which has been isolated from garden soil in Japan. Streptomyces nitrosporeus produces Benzastatin E, Benzastatin F, Benzastatin G Nitrosporeusine A and Nitrosporeusine B and the antibiotics nitrosporin and virantomycin and the inhibitor of angiotensin-converting enzyme foroxymithine. Streptomyces nitrosporeus can degrade cellulose.
Thiocoraline is a microbial natural product of the depsipeptide class. Thiocoraline was isolated from the mycelium cake of a marine actinomycete strain L-13-ACM2-092. In vitro, thiocoraline causes an arrest in G1 phase of the cell cycle and decreases the rate of S phase progression towards G2/M phase. Thiocoraline is likely to be a DNA replication inhibitor. Thiocoraline is produced on a nonribosomal peptide synthetase (NRPS) assembly line.
