4TTM

Racemic structure of kalata B1 (kB1)

Summary for 4TTM

• Entry DOI: 10.2210/pdb4ttm/pdb
• Descriptor: Kalata-B1, D-kalata B1 (3 entities in total)
• Functional Keywords: cyclic peptide, disulfide bonds, plant protein
• Biological source: Oldenlandia affinis; More
• Total number of polymer chains: 2
• Total formula weight: 5834.69

Authors

Wang, C.K.,King, G.J.,Craik, D.J. (deposition date: 2014-06-22, release date: 2014-09-10, Last modification date: 2024-11-06)

Primary citation

Wang, C.K.,King, G.J.,Northfield, S.E.,Ojeda, P.G.,Craik, D.J.
Racemic and Quasi-Racemic X-ray Structures of Cyclic Disulfide-Rich Peptide Drug Scaffolds.
Angew.Chem.Int.Ed.Engl., 53:11236-11241, 2014

PubMed Abstract: Cyclic disulfide-rich peptides have exceptional stability and are promising frameworks for drug design. We were interested in obtaining X-ray structures of these peptides to assist in drug design applications, but disulfide-rich peptides can be notoriously difficult to crystallize. To overcome this limitation, we chemically synthesized the L- and D-forms of three prototypic cyclic disulfide-rich peptides: SFTI-1 (14-mer with one disulfide bond), cVc1.1 (22-mer with two disulfide bonds), and kB1 (29-mer with three disulfide bonds) for racemic crystallization studies. Facile crystal formation occurred from a racemic mixture of each peptide, giving structures solved at resolutions from 1.25 Å to 1.9 Å. Additionally, we obtained the quasi-racemic structures of two mutants of kB1, [G6A]kB1, and [V25A]kB1, which were solved at a resolution of 1.25 Å and 2.3 Å, respectively. The racemic crystallography approach appears to have broad utility in the structural biology of cyclic peptides.

PubMed: 25168664
DOI: 10.1002/anie.201406563

Experimental method

X-RAY DIFFRACTION (1.9001 Å)