Highly conserved HPV16 L2 cysteines C22 and C28 are not reactive with BMCC-biotin in native virions.

<p>(A) Primary amino acid sequence alignment of L2 proteins from various members of the Family <i>Papillomaviridae</i> shows conservation of C22 and C28 (HPV16) across divergent <i>genera</i>. (B) Amine and thiol biotinylation assays of HPV16 virions. Purified virions were either mock treated (native) or DTT treated (reduced) prior to incubation with amine reactive NHS-biotin or thiol reactive BMCC-biotin. Biotinylated proteins were separated by SDS-PAGE, transferred to membranes, and detected with streptavidin-HRP. Note that L2 cysteines are only reactive when the virions are reduced prior to labeling.