What is it? Protein disulphide isomerase is an enzyme with two interrelated activities: as an oxidoreductase, it can catalyse the formation, reduction and isomerisation of disulphide bonds; and as a polypeptide binding protein, it can function as a molecular chaperone which assists the folding of polypeptides. Transient association of PDI with nascent polypeptides during their folding prevents ...

We examine a simple model of rotaxane structure, with 3 asymmetric rings interacting via repulsive power-law forces. This interlocked molecule exhibits conformational isomerisation which is different from that of molecules whose connectedness is through covalent bonds. The rings are free to translate along and rotate around the axle, and hence weak interaction forces between the rings can lead ...

Few methods currently exist for controlling vesicle-vesicle adhesion. We now report a new system, based upon a multivalent guest and an amphiphilic receptor with a photo-isomerisable anchor that can be incorporated into lipid vesicles of different sizes. Large unilamellar vesicles containing our receptor were found to aggregate upon addition of the multivalent guest, independently of photoswitc...

We report a dynamical-mechanical study of stress relaxation at small deformation in a natural (polyisoprene) rubber well above its glass transition temperature Tg. We find that an almost complete relaxation of stress takes place over very long relaxation periods, even though the elastic network is retained. The relaxation rate and the long-time equilibrium modulus are sensitive functions of tem...