Oligomeric nature of transmembrane glycoproteins of HIV-2: procedures for their efficient dissociation and preparation of Western blots for diagnosis.
Western blot (WB) analysis of various strains of HIV-2 indicated that transmembrane glycoprotein (TMP) of HIV-2 exists as trimers. These trimers have molecular weights and electrophoretic mobilities in the region of the major external glycoprotein, gp120, resulting in WB misidentification during diagnosis. A simple and rapid procedure was developed using trichloroacetic acid (TCA) to efficiently dissociate oligomeric forms of the TMP to monomers prior to the preparation of WB. This procedure permitted the unambiguous identification of antibodies to gp120 and to the TMP. Use of HIV-2 WB strips without any oligomeric forms of the TMP demonstrated (1) that cross reactivity of HIV-1-positive specimens on HIV-2 WB was mainly directed to Gag and Pol proteins, with some reactivity to gp36/gp41 TMP, but none to gp120; (2) that these strips can substantially reduce the number of specimens falsely identified as dually (HIV-1 and HIV-2) reactive; and (3) that HIV-2-positive specimens reacted to viral gp120 in a strain-specific manner, demonstrating high antigenic variation in this glycoprotein. It is recommended that this general procedure of viral protein dissociation be used for HIV-2 WB preparation.
Parekh
B S
BS
Laboratory Investigations Branch, Centers for Disease Control, Atlanta, Georgia 30333.
Pau
C P
CP
Granade
T C
TC
Rayfield
M
M
De Cock
K M
KM
Gayle
H
H
Schochetman
G
G
George
J R
JR
D015153:Blotting, Western / Q000379:methods*; D015686:Gene Products, env / Q000737:chemistry / Q000302:isolation & purification; D015483:HIV Antibodies / Q000032:analysis; D015488:HIV Antigens / Q000737:chemistry / Q000302:isolation & purification; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000302:isolation & purification; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000302:isolation & purification; D015658:HIV Infections / Q000175:diagnosis / Q000276:immunology; D015498:HIV-2 / Q000737:chemistry*; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000302:isolation & purification*; D011487:Protein Conformation; D011498:Protein Precursors / Q000737:chemistry / Q000302:isolation & purification; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000302:isolation & purification*; D054299:env Gene Products, Human Immunodeficiency Virus
D015686:Gene Products, env; D015483:HIV Antibodies; D015488:HIV Antigens; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41; D008562:Membrane Glycoproteins; D011498:Protein Precursors; D014759:Viral Envelope Proteins; D054299:env Gene Products, Human Immunodeficiency Virus; C059763:env protein gp36, Human immunodeficiency virus