TY - JOUR AU - Olajos, Gábor AU - Hetényi, Anasztázia AU - Wéber, Edit AU - Szögi, Titanilla AU - Fülöp, Lívia AU - Martinek, Tamás TI - Peripheral cyclic β-amino acids balance the stability and edge-protection of β-sandwiches JF - ORGANIC & BIOMOLECULAR CHEMISTRY J2 - ORG BIOMOL CHEM VL - 16 PY - 2018 IS - 30 SP - 5492 EP - 5499 PG - 8 SN - 1477-0520 DO - 10.1039/c8ob01322e UR - https://m2.mtmt.hu/api/publication/3399101 ID - 3399101 N1 - Funding text: This work was supported by the Hungarian Academy of Sciences, Lendulet program (LP-2011-009) and GINOP-2.3.3-15-2016-00010. E. W. thanks the Postdoctoral Fellowship Program 2014 of the Hungarian Academy of Sciences. AB - Engineering water-soluble stand-alone beta-sandwich mimetics is a current challenge because of the difficulties associated with tailoring long-range interactions. In this work, single cis-(1R,2S)-2-aminocyclohexanecarboxylic acid mutations were introduced into the edge strands of the eight-stranded beta-sandwich mimetic structures from the betabellin family. Temperature-dependent NMR and CD measurements, together with thermodynamic analyses, demonstrated that the modified peripheral strands exhibited an irregular and partially disordered structure but were able to exert sufficient shielding on the hydrophobic core to retain the predominantly beta-sandwich structure. Although the frustrated interactions decreased the free energy of unfolding, the temperature of the maximum stabilities increased to or remained at physiologically relevant temperatures. We found that the irregular peripheral strands were able to prevent edge-to-edge association and fibril formation in the aggregation-prone model. These findings establish a beta-sandwich stabilization and aggregation inhibition approach, which does not interfere with the pillars of the peptide bond or change the net charge of the peptide. LA - English DB - MTMT ER -