New Disulphide Bond in Cystatin-Based Protein Scaffold Prevents Domain-Swap-Mediated Oligomerization and Stabilizes the Functionally Active Form.

ABSTRACT: Peptide aptamers built using engineered scaffolds are a valuable alternative to monoclonal antibodies in many research applications because of their smaller size, versatility, specificity for chosen targets, and ease of production. However, inserting peptides needed for target binding may affect the aptamer structure, in turn compromising its activity. We have shown previously that a stefin A-based protein scaffold with AU1 and Myc peptide insertions (SQT-1C) spontaneously forms dimers and tetramers and that inserted loops mediate this process. In the present study, we show that SQT-1C forms tetramers by self-association of dimers and determine the kinetics of monomer-dimer and dimer-tetramer transitions. Using site-directed mutagenesis, we show that while slow domain swapping defines the

SUBMITTER: Zalar M 

PROVIDER: S-EPMC6844092 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature