Isolation and Morphology of the Internal Component of Human Coronavirus, Strain 229E

Abstract

Biochemical studies on human coronavirus, strain 229E, indicate that the RNA is present in the virion in association with protein as a ribonucleoprotein (RNP) complex. Morphological studies have revealed that this nucleocapsid is probably a continuous helical RNP.

Preliminary studies on the isolation of coronavirus 229E nucleocapsids

“…The purified nucleocapsid-like structures observed here are morphologically different from those previously reported by Kennedy and Johnson-Lussenburg [9] who purified and detergent-treated 229E virus in a similar manner. The differences between the morphology of the previously described structures and those reported here could be explained by the electron microscopical preparative procedures used.…”

“…Although several members of this group have been characterized biochemically [3][4][5][6][7] little is known about the morphology of the internal component. Apostolov and Flewett [8] observed 7-8 nm threads in thin sections of pelleted preparations of avian infectious bronchitis virus and Kennedy and Johnson-Lussenburg [9] isolated the internal component of the human respiratory coronavirus 229E and described its morphology from negatively stained preparations. However, Macnaughton et al [10] recently described the morphology following negative staining of ribonucleoprotein (RNP)-like structures in their preparations of 229E virus which were clearly dissimilar, both in diameter and appearance to those previously reported [9].…”

“…Apostolov and Flewett [8] observed 7-8 nm threads in thin sections of pelleted preparations of avian infectious bronchitis virus and Kennedy and Johnson-Lussenburg [9] isolated the internal component of the human respiratory coronavirus 229E and described its morphology from negatively stained preparations. However, Macnaughton et al [10] recently described the morphology following negative staining of ribonucleoprotein (RNP)-like structures in their preparations of 229E virus which were clearly dissimilar, both in diameter and appearance to those previously reported [9]. Nucleocapsid-like structures, 9 nm in diameter, have been observed in thin sections of organ cultures infected with the human enteric coronavirus [11 ].…”

In vivo and in vitro Models of Demyelinating Diseases

“…the diameter of the helical nucleocapsid of the paramyxoviruses, measuring 15-19 nm [24,32,33], is about double the width of the coronavirus cores. According to another recent interpretation, the coronavirus nucleocapsid structure is described as a circular, dense, inner component, about 60 nm in diameter [7], Our new evidence, coupled with information ob tained on disrupted negatively stained 229E virions [29,31] and on another representative of the group [30], indicate that the architecture of the coronaviruses simulates that of the orthomyxo-and paramyxoviruses, although the coronaviruses, unlike the other two groups, possess a single-stranded RNA genome of the + sense. From this observation it may be con cluded that polarity of the RNA genome and helical conformation of the nucleoprotein are not necessarily interrelated.…”

Studies on the Structure of a Coronavirus-Avian Infectious Bronchitis Virus

“…and have characteristic club shaped surface projections Io to 11 nm in length. Prepared by the thin sectioning technique, coronaviruses generally appear rounded (Becket et al No interior ribonucleoprotein strand has been seen in any negatively stained preparations, although there has been one report of a helical component released from virions of the human coronavirus, strain 229E (Kennedy & Johnson-Lussenberg, 1976). Occasionally electron-dense structures in the centre of virus particles have been observed in ultrathin sections (Apostolov et al I97o;S.…”