Catalyzes the dye-linked oxidation of primary alcohols to the corresponding aldehydes and the (subsequent) oxidation of the aldehydes to carboxylic acids. Exhibits activity with longer mono-alcohols (C-4 to C-7) but not with methanol or glycerol. Reacts with 1,2-propanediol and 1,3-propanediol but not with sugar alcohols such as D-sorbitol. a primary alcohol + 2 oxidized [azurin] = an aldehyde + 2 H(+) + 2 reduced [azurin] Binds 1 PQQ group per subunit. PQQ is inserted between disulfide Cys-127-Cys-128 and the plane of Trp-254. Binds 1 Ca(2+) ion per subunit. Binds 1 heme c group per subunit. Inhibited by 10 mM 1-butanol. Optimum pH is 8.0. E(0) is +185 mV for heme c at pH 7.0, +188 mV for heme c at pH 8.0, +172 mV for heme c at pH 8.0 and 0.3 M KCl and +189 mV for ADH IIB-Azurin complex. Monomer. By 1-butanol. Primary and secondary C3,C4 alcohols as well as butyraldehyde. The measured mass is that of QbdA with a single heme bound. Belongs to the bacterial PQQ dehydrogenase family.