Download MendeleyThe Single Disulfide-Directed beta-Hairpin Fold. Dynamics, Stability, and Engineering.
Chittoor, B., Krishnarjuna, B., Morales, R.A.V., MacRaild, C.A., Sadek, M., Leung, E.W.W., Robinson, S.D., Pennington, M.W., Norton, R.S.(2017) Biochemistry 56: 2455-2466
- PubMed: 28437072
- DOI: https://doi.org/10.1021/acs.biochem.7b00120
- Primary Citation of Related Structures:
5KKM - PubMed Abstract:
Grafting bioactive peptide sequences onto small cysteine-rich scaffolds is a promising strategy for enhancing their stability and value as novel peptide-based therapeutics. However, correctly folded disulfide-rich peptides can be challenging to produce by either recombinant or synthetic means. The single disulfide-directed β-hairpin (SDH) fold, first observed in contryphan-Vc1, provides a potential alternative to complex disulfide-rich scaffolds. We have undertaken recombinant production of full-length contryphan-Vc1 (rCon-Vc1[Z1Q]) and a truncated analogue (rCon-Vc1 1-22 [Z1Q]), analyzed the backbone dynamics of rCon-Vc1[Z1Q], and probed the conformational and proteolytic stability of these peptides to evaluate the potential of contryphan-Vc1 as a molecular scaffold. Backbone 15 N relaxation measurements for rCon-Vc1[Z1Q] indicate that the N-terminal domain of the peptide is ordered up to Thr19, whereas the remainder of the C-terminal region is highly flexible. The solution structure of truncated rCon-Vc1 1-22 [Z1Q] was similar to that of the full-length peptide, indicating that the flexible C-terminus does not have any effect on the structured domain of the peptide. Contryphan-Vc1 exhibited excellent proteolytic stability against trypsin and chymotrypsin but was susceptible to pepsin digestion. We have investigated whether contryphan-Vc1 can accept a bioactive epitope while maintaining the structure of the peptide by introducing peptide sequences based on the DINNN motif of inducible nitric oxide synthase. We show that sCon-Vc1 1-22 [NNN 12-14 ] binds to the iNOS-binding protein SPSB2 with an affinity of 1.3 μM while maintaining the SDH fold. This study serves as a starting point in utilizing the SDH fold as a peptide scaffold.
Organizational Affiliation:
Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia.
