Anti-aggregatory effect of cyclodextrins in the refolding process of recombinant growth hormones from Escherichia coli inclusion bodies.

Cyclodextrins with different ring size and ring substituents were tested for recombinant mink and porcine growth hormones aggregation suppression in the refolding process from Escherichia coli inclusion bodies. Methyl-beta-cyclodextrin and 2-hydroxypropyl-beta-cyclodextrin show a positive effect on the aggregation suppression of both proteins. The influence of different methyl-beta-cyclodextrin and 2-hydroxypropyl-beta-cyclodextrin concentrations on the renaturation yield of both growth hormones was investigated. Moreover, methyl-beta-cyclodextrin and 2-hydroxypropyl-beta-cyclodextrin suppress not only folding-related, but also temperature-related aggregates formation of both proteins. Circular dichroism experiments (monitoring of protein solution turbidity by registering high tension voltage) showed that the onset temperature of aggregation of both growth hormones increased with increasing 2-hydroxypropyl-beta-cyclodextrin concentration. In conclusion, cyclodextrins have perspectives in biotechnology of veterinary growth hormones not only for protein production, but also for its storage.