Avtor/Urednik		Žerovnik, Eva; Pompe-Novak, Maruša; Škarabot, Miha; Ravnikar, Maja; Muševič, Igor; Turk, Vito
Naslov		Human stefin B readily forms amyoid fibrils in vitro
Tip		članek
Vir		Biochim Biophys Acta
Vol. in št.		Letnik 1594, št. 1
Leto izdaje		2002
Obseg		str. 1-5
Jezik		eng
Abstrakt		Human stefin B (cystatin B) is an intracellular cysteine proteinase inhibitor broadly distributed in different tissues. Here, we show that recombinant human stefin B readily forms amyloid fibrils in vitro. It dimerises and further oligomerises, starting from the native-like acid intermediate, IN populated at pH 5. On standing at room temperature it produces regular (over 4 micri m long) fibrils over a period of several months, These have been visualised by transmission electron microscopy and atomic force microscopy. Their cross-sectioal diameter is about 14 nm and blocks of 27 nm repeat longitudinally. The fibrils are smooth, of unbranched surface, consistent with findings of other amyloid fibrils. Thioflavin T fluorescence spectra as a function of time were recorded and Congo red dye binding to the fibrils was demonstrated. Adding 10% (v/v) trifluoroethanol resulted in an increased rate of fibrillation with a typical lag phase. The finding that human stefm B, in contrast to the homologue stefin A forms amyloid fibrils rather easily should promote further studies of the protein's behaviour in vivo, and/or as a model system for fibrillogenesis.
Deskriptorji		AMYLOID BETA-PROTEIN CYSTATINS CYSTEINE PROTEINASE INHIBITORS BUFFERS CONGO RED DYES HYDROGEN-ION CONCENTRATION MICROSCOPY, ATOMIC FORCE MICROSCOPY, ELECTRON PROTEIN CONFORMATION RECOMBINANT PROTEINS THIAZOLES X-RAY DIFFRACTION