Structural studies on avian myeloblastosis virus: Conditions for isolation and biochemical characteristics of the core component

The Organization of Mature Rous Sarcoma Virus as Studied by Cryoelectron Microscopy

“…Isolation and biochemical analysis of the core have been reported for a number of retroviruses (Fukui et al, 1993;Kotov et al, 1999;Accola et al, 2000;Welker et al, 2000;Palmer et al, 1988;Chrystie and Almeida, 1989;Benzair et al, 1986;Roberts and Oroszlan, 1989;Nermut et al, 1972;Lange et al, 1973;Bolognesi et al, 1972Bolognesi et al, , 1973Teramoto et al, 1977;Bader et al, 1970;Stromberg, 1972;Stromberg et al, 1973). A general conclusion from these studies is that the retroviral core appears to be fragile, and inherently unstable, once the viral membrane has been removed.…”

“…This sequence of steps may have proved sufficient to disrupt the lipid envelopes of some of the virions. The isolation of cores from avian retroviruses, through the detergent treatment of mature virions, has been reported previously (Bader et al, 1970;Bolognesi et al, 1972;Stromberg, 1972;Stromberg et al, 1973). Cores isolated in this fashion appeared to be mechanically fragile and were obtained in low yield.…”

Structural Studies of Avian Myeloblastosis Virus: Absence of Leukemogenic Activity of the Core Component

“…Table I compares the leukemogenic activity of AMV virions and AMV cores which were isolated either by means of isopycnic centrifugation or velocity centrifugation ( 8 ) . Table I compares the leukemogenic activity of AMV virions and AMV cores which were isolated either by means of isopycnic centrifugation or velocity centrifugation ( 8 ) .…”

“…Table I compares the leukemogenic activity of AMV virions and AMV cores which were isolated either by means of isopycnic centrifugation or velocity centrifugation ( 8 ) . Conditions for core isolation ( 8 ) incluclcd rcsuspcnsion o f this p11rified . However, with either method of isolation, it is evident from Table I that the AMV core component, at concentrations of between 50 pg and 330 pug of viral protein injected per chick, was not capable of inducing myeloblastosis in a total of 40 neonatal chicks.…”

“…Evaluation of the latter, more rapid method of core isolation was considered important because the prolonged technique of isopycnic centrifugation might remove biologic activity of AMV cores. The core component of .4MV was obtained by either isopycnic centrifugation or velocity centrifugation (8) ; however, in both cases, cadi 2 In1 of this purified ;lXlV was treated for 1 0 niin a t oo with 0.5 nil of a 7..5yo v / v concentration of the nonionic surfactant, Steros SL (7) . In contrast, intraperitoneal injection of AMV virions caused an incidence of leukemia of approximately 55% for virions obtained by velocity centrifugation and 70% for virions obtained following isopycnic centrifugation.…”