id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-353467-wbtzvm4i	Lambert, Carsten	Functional incorporation of green fluorescent protein into hepatitis B virus envelope particles	2004-12-05		.txt	text/plain	6316	307	50	In the late stages of an HBV infection, progeny virions are formed by budding of the pre-assembled cytosolic nucleocapsids, enclosing the partially double-stranded DNA genome 3.2 kb in length and the viral polymerase through intracellular membranes accommodating the viral envelope proteins (for review, see Nassal, 1996) . To determine whether the co-secreted GFP.S and SHA proteins resembled authentic subviral HBV envelope particles, the culture supernatant of transfected cells was fractionated by isopycnic CsCl gradient centrifugation and fractions were analyzed by an S-specific ELISA. According to current models for the transmembrane structure of S, its N-terminus and hence the GFP fusion site are located to the lumenal side of intracellular membranes that is topologically equivalent to the virion surface ( Fig. 4A ) (Berting et al., 1995; Stirk et al., 1992) . Here we applied this approach to hepatitis B virus and obtained fluorescent subviral and viral particles by incorporation of the viral S envelope protein, tagged with GFP, in trans, thereby preserving all the functions necessary for the viral life cycle.	./cache/cord-353467-wbtzvm4i.txt	./txt/cord-353467-wbtzvm4i.txt