Fig. 1

Disulphide bond formation in the model proteins. AMS alkylation and Western blot analysis with antibodies raised against AmlB (a) and DagA (b) were performed to determine the presence of disulphide bonds in the proteins studied. Samples from supernatants of overproducing alpha-amylase and agarase strains (a, b) were treated with the alkylated agent AMS (+) (lane 1 and 3) or not (−) (lane 2 and 4) and with the reducing agent DTT (+) (lane 1 and 2) or not (−) (lane 3 and 4). AMS reacts with the free thiol groups, so retarded mobility in the alkylated proteins indicated presence of reduced thiol groups. Samples not incubated with AMS were used as non-alkylated controls. The mobility of the reduced (red) and oxidised (oxd) forms of the model proteins is indicated