FIG. 6.
Determination of biotin binding sites of SAV purified from WB800BIO(pSSAV-Tcry) by competitive ELISA. SAV was purified from WB800BIO(pSSAV-Tcry) cultured in CA medium containing vitamin-free Casamino Acids. Bound HRP activity was determined using a one-step slow-TMB ELISA (Pierce) as the substrate. The number of biotin binding sites on SAV was estimated at 50% of bound-HRP activity using SAV from Roche Molecular Biochemicals (for which the number of biotin binding sites is 4) as the reference. SAV purified from WB800BIO(pSSAV-Tcry) cultured in CA medium containing regular Casamino Acids showed an almost identical competition profile as that observed for SAV purified from CA medium containing vitamin-free Casamino Acids. For clarity, data for SAV purified from CA medium containing regular Casamino Acids are not presented. •, SAV purified from WB800BIO(pSSAV-Tcry); ▴, reference SAV from Roche Molecular Biochemicals.
