Tyropeptins A and B, new proteasome inhibitors produced by Kitasatospora sp. MK993-dF2. I. Taxonomy, isolation, physico-chemical properties and biological activities.
Tyropeptins A and B, new proteasome inhibitors, were isolated from the culture broth of Kitasatospora sp. MK993-dF2. They were purified using ethyl acetate extraction, silica gel column chromatography, Sephadex LH-20 column chromatography and HPLC. Tyropeptin A inhibited the chymotrypsin-like (ChT-L) and trypsin-like (T-L) activities of 20S proteasome with IC50 values of 0.1 microg/ml and 1.5 microg/ml respectively, but did not inhibit the peptidylglutamyl-peptide hydrolyzing (PGPH) activity of 20S proteasome at a concentration of 100 microg/ml. The inhibitory activities of tyropeptin A were about two times as strong as that of tyropeptin B. Taxonomy of the producing strain is also described.
Momose
I
I
Institute of Microbial Chemistry, Tokyo, Japan. imomose@bikaken.or.jp
Sekizawa
R
R
Hashizume
H
H
Kinoshita
N
N
Homma
Y
Y
Hamada
M
M
Iinuma
H
H
Takeuchi
T
T
D000818:Animals; D003546:Cysteine Endopeptidases; D004151:Dipeptides / Q000302:isolation & purification* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors*; D046988:Proteasome Endopeptidase Complex
D004151:Dipeptides; D004791:Enzyme Inhibitors; D009097:Multienzyme Complexes; C449021:tyropeptin A; C449020:tyropeptin B; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex