Figure 1.

Subfractionation of cauliflower microsomes by Suc gradient centrifugation. A, Suc concentrations (●) determined by refractometry, and distribution of protein (□) among microsomal subfractions. B, Distribution of ER and vacuolar marker enzyme activities. ○, Bafilomycin A₁-sensitive H⁺-ATPase (100% = 99.4 nmol mg⁻¹ min⁻¹); ▪, antimycin A-insensitive NADH-Cyt c reductase (100% = 59.5 nmol mg⁻¹ min⁻¹). C, Western analysis of microsomal subfractions (10 μg protein per lane) decorated with antibodies against calnexin (1:1,000 diluted). The arrow indicates 65 kD cauliflower calnexin.