8amy

Publication Abstract from PubMed

Marine cone snails produce a wealth of peptide toxins (conotoxins) that bind their molecular targets with high selectivity and potency. Therefore, conotoxins constitute valuable biomolecular tools with a variety of biomedical purposes. The Mu8.1 conotoxin from Conus mucronatus is the founding member of the newly identified saposin-like conotoxin class of conotoxins and has been shown to target Cav2.3, a voltage-gated calcium channel. Two crystal structures have recently been determined of Mu8.1 at 2.3 and 2.1 A resolution. Here, a high-resolution crystal structure of Mu8.1 was determined at 1.67 A resolution in the high-symmetry space group I4(1)22. The asymmetric unit contained one molecule, with a symmetry-related molecule generating a dimer equivalent to that observed in the two previously determined structures. The high resolution allows a detailed atomic analysis of a water-filled cavity buried at the dimer interface, revealing a tightly coordinated network of waters that shield a lysine residue (Lys55) with a predicted unusually low side-chain pK(a) value. These findings are discussed in terms of a potential functional role of Lys55 in target interaction.

High-resolution crystal structure of the Mu8.1 conotoxin from Conus mucronatus.,Muller E, Hackney CM, Ellgaard L, Morth JP Acta Crystallogr F Struct Biol Commun. 2023 Sep 1;79(Pt 9):240-246. doi: , 10.1107/S2053230X23007070. Epub 2023 Aug 29. PMID:37642664^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.