Ej. Wolffe et al., A MYRISTYLATED MEMBRANE-PROTEIN ENCODED BY THE VACCINIA VIRUS L1R OPEN READING FRAME IS THE TARGET OF POTENT NEUTRALIZING MONOCLONAL-ANTIBODIES, Virology, 211(1), 1995, pp. 53-63
We identified a protein component of the intracellular mature vaccinia
virion membrane that is a target of a potent neutralizing monoclonal
antibody, 7D11, obtained from Alan L. schmaljohn. By immunofluorescent
and electron microscopic analysis, MAb 7D11 was found to stain intrac
ytoplasmic viral factories, virion membranes in cell sections, and the
surface of negatively stained preparations of purified virions. The M
Ab 7D11 antigen, which is synthesized at late times in infection, has
apparent molecular masses of 25 and 29 kDa under nonreducing and reduc
ing conditions, respectively. The membrane antigen was most efficientl
y extracted from virions by NP40 detergent in combination with a reduc
ing agent; in addition, the protein partitioned exclusively into the d
etergent phase when extracted with Triton X-114. Although the N-termin
us of the immunoaffinity-purified protein was blocked, sequence analys
is of trypic peptides revealed that the MAb 7D11 antigen was identical
to the myristylated protein encoded by the L1R open reading frame pre
viously described by C. A. Franke, E. M. Wilson, and D. E. Hruby (1990
, J. Virol. 64, 5988-5996). Validation of this genetic assignment was
provided by the ability of MAb 7D11 to immunoprecipitate a [H-3]myrist
ic acid-labeled product of the expected molecular weight from infected
cells. In addition, we discovered that the previously described neutr
alizing monoclonal antibody 205 (Y. Ichihashi, T. Takahashi, and M. Oi
e, 1994, Virology 202, 834-843) also recognizes the L1R protein. (C) 1
995 Academic Press, Inc.