Search results
Results from the WOW.Com Content Network
α-Amanitin Bacitracin Ciclosporin. Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. [1] This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains ...
The compound features a six-membered ring containing two amide groups at opposite positions in the ring. It was first compound containing a peptide bond to be characterized by X-ray crystallography in 1938. [1] It is the parent of a large class of 2,5-Diketopiperazines (2,5-DKPs) with the formula (NHCH 2 (R)C(O)) 2 (R = H, CH 3, etc.).
Cyclic glycine-proline (cGP) is a small neuroactive peptide that belongs to a group of bioactive 2,5-diketopiperazines (2,5-DKPs) and is also known as cyclo-glycine-proline. cGP is a neutral, stable naturally occurring compound and is endogenous to the human body; found in human plasma, breast milk and cerebrospinal fluid.
DKP's are the smallest known class of cyclic peptide. [1] Despite their name, they are not ketones, but amides. Three regioisomers are possible, differing in the locations of the carbonyl groups. Retosiban [2] is a diketopiperazine being investigated as an oral drug. One isomer is an oxamide obtained from ethylenediamine.
In organic chemistry, peptide synthesis is the production of peptides, compounds where multiple amino acids are linked via amide bonds, also known as peptide bonds. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another.
Ciclosporin is a cyclic peptide of 11 amino acids; it contains a single D-amino acid, which is rarely encountered in nature. Unlike most peptides, ciclosporin is not synthesized by ribosomes. [44] Ciclosporin is highly metabolized by the CYP3A4 enzyme in humans and animals after ingestion. [45]
Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP. Its most likely mechanism of action is activation of intracellular protein kinases in response to the binding of membrane-impermeable peptide hormones to the external cell surface. [1]
[3] Circular peptides tend to be resistant to protease activity, and may be suitable for use as orally administered drugs. Once a cyclic peptide is identified with a biological activity of interest, it may also be possible to identify the target of the peptide (a gene that encodes a protein with which it interacts) by functional complementation ...