Thermodynamic and hydrodynamic study of Bence-Jones proteins

Role of cis- and trans-interactions in manifestations of amyloidogenic properties of variable domains of Bence-Jones proteins TIM and LUS

“…Similar data were also obtained for the LUS protein and its fragments. The data suggest a block structure of the protein because the calorimetric enthalpy is much higher than the effec tive one (calculated also from optical curves of the melt ing, see table) that is specific for the Bence Jones proteins [9,10,18]. For interpretation of the results, it was neces sary to establish just what domains could form the blocks and also to determine thermodynamic parameters of these cooperative structures.…”

“…This fragment was prepared by the standard method from antibodies (rabbit IgG) against the LUS variable domains. This approach was earlier shown to significant ly increase the yield of those constant domains, the sta bility of which significantly decreased on limited proteo lysis of the Bence Jones proteins VAD and PER [9,10]. This approach was also productive for preparing variable domains of the protein LUS and resulted in more than twofold increase in the yield of intact domains upon the proteolysis.…”

“…But because the yield of variable domains in the case of pro tein LUS was decreased, the method was modified as fol lows: not the isolated protein LUS was subjected to limit ed proteolysis, but its complex with the Fab fragment [9]. This fragment was prepared by the standard method from antibodies (rabbit IgG) against the LUS variable domains.…”

“…4b and the table). Based on earlier data obtained for both Bence Jones proteins [9,10,18] and for the Fab fragments [34,35], it was sup posed that they could be formed by a pair of the constant and a pair of the variable domains.…”

“…Interdomain interactions, which can level the whole amyloidogenic potential recorded in the isolat ed domains, must be also considered [9,10].…”