Identification of a α-helical molten globule intermediate and structural characterization of β-cardiotoxin, an all β-sheet protein isolated from the venom of Ophiophagus hannah (king cobra).

ABSTRACT: β-Cardiotoxin is a novel member of the snake venom three-finger toxin (3FTX) family. This is the first exogenous protein to antagonize β-adrenergic receptors and thereby causing reduction in heart rates (bradycardia) when administered into animals, unlike the conventional cardiotoxins as reported earlier. 3FTXs are stable all β-sheet peptides with 60-80 amino acid residues. Here, we describe the three-dimensional crystal structure of β-cardiotoxin together with the identification of a molten globule intermediate in the unfolding pathway of this protein. In spite of the overall structural similarity of this protein with conventional cardiotoxins, there are notable differences observed at the loop region and in the charge distribution on the surface, which are known to be critical for cytoly

SUBMITTER: Roy A 

PROVIDER: S-EPMC6459992 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature