title: Isolation of plactins A, B, C and D, novel cyclic pentapeptides that stimulate cellular fibrinolytic activity.
abstract: Four novel cyclic pentapeptides, designated plactins A, B, C and D, were isolated by solvent extraction and reverse-phase HPLC from mycelium of a fungal strain F165 that belongs to the order of Agonomycetales. By a combination of chemical and spectroscopic analyses and chemical synthesis, the structures of plactins A, B, C and D were determined to be cyclo(-D-Val-L-Leu-D-alloIle-L-Try-D-Arg-), cyclo(-D-Val-L-Leu-D-Leu-L-Tyr-D-Arg-), cyclo(-D-Val-L-Leu-D-alloIle-L-Phe-D-Arg-) and cyclo(-D-Val-L-Leu-D-Leu-L-Phe-D-Arg-), respectively. Plactins stimulated U937 cell-mediated degradation of 125I-fibrin plates by 50% at a concentration of 7.5 approximately 32 microM.
authors.affiliation: Department of Applied Biological Science, Tokyo Noko University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Hasumi
authors.forename: T
authors.initials: T
authors.lastname: Kuniyasu
authors.forename: A
authors.initials: A
authors.lastname: Endo
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D005285:Fermentation; D005337:Fibrin / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D003904:Mitosporic Fungi / Q000145:classification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D005343:Fibrinolytic Agents; D010456:Peptides, Cyclic; C098359:plactin A; C098360:plactin B; C098361:plactin C; C098362:plactin D; D005337:Fibrin