Cell surface expression of M2tag and
M2-V27S oligomers in oocytes of X.
laevis. Synthetic mRNAs encoding M2tag,
M2-V27S, or a mixture of the two RNAs and using
water as a control were microinjected (50 nl of RNA of 0.85
μg/μl for M2tag, 50 nl of 0.25
μg/μl for M2-V27S, and 50 nl of
RNA containing 0.75 μg/μl M2tag mixed with
0.25 μg/μl M2-V27S) into oocytes
of X. laevis. At 24 h after injection, oocytes were
labeled with [35S]methionine for 18 h and
surface-expressed M2 protein captured with
M2-specific mAb (14C2). Oocytes were washed, homogenized,
and detergent lysates prepared in the presence of 50 mM iodoacetamide
as described. Antibody was recovered by adding protein A-Sepharose
beads and immune complexes were analyzed by SDS/PAGE under
nonreducing conditions.