Avtor/Urednik | Kastelic, L; Turk, B; Kopitar-Jerala, N; Štolfa, A; Rainer, S; Turk, V; Lah, TT | |
Naslov | Stefin B, the major low molecular weight inhibitor in ovarian carcinoma | |
Tip | članek | |
Vir | Cancer Lett | |
Vol. in št. | Letnik 82, št. 1 | |
Leto izdaje | 1994 | |
Obseg | str. 81-8 | |
Jezik | eng | |
Abstrakt | Endogenous cysteine proteinase inhibitors (CPIs) presumably regulate lysosomal cysteine endopeptidases (CPs), such as cathepsins B and L, in vivo. An imbalance between CPs and CPIs in carcinomas, possibly due to impaired inhibition of proteinases, was reported. Ovarian carcinoma contain high levels of Stefin B and about twentyfold less Stefin A compared to normal epithelial tissue. Stefin B was isolated and characterized. We used alkaline treatment, affinity chromatography on Cm-papain Sepharose, followed by gel filtration and ion-exchange chromatography and anti-Stefin B-Sepharose 4B to isolate two major isoforms of Stefin B with pI values 5.9 and 6.5. M(r) of ovarian Stefin B was close to 14,000 as judged by SDS-PAGE and had a blocked N-terminus. It strongly inhibited papain (Ki = 0.11 nM) and cathepsin L (Ki = 0.035 nM), but only moderately cathepsin B (Ki = 130 nM). As these properties are similar to Stefin B from human and bovine origin, as well as to Stefin B from human histiosarcoma, we believe that tumor Stefin B does not differ from normal Stefin B. | |
Deskriptorji | CYSTATINS CYSTEINE PROTEINASE INHIBITORS CHROMATOGRAPHY, AFFINITY CHROMATOGRAPHY, HIGH PRESSURE LIQUID CYSTATINS ISOELECTRIC FOCUSING OVARIAN NEOPLASMS |