Biophysics

The bacterial flagellar motor can rotate in both counterclockwise (CCW) and clockwise (CW) directions. It has been shown that the sodium ion-driven chimeric flagellar motor rotates with 26 steps per revolution, which corresponds to the number of FliG subunits that form part of the rotor ring, but the size of the backward step is smaller than the forward one. read moreRead Full Story

The structural and functional conversion of the nonselective NaK channel to a K+ selective channel (NaK2K) allows us to identify two key residues, Tyr and Asp in the filter sequence of TVGYGD, that participate in interactions central to stabilizing the K+ channel selectivity filter. read moreRead Full Story

Many voltage-gated ion channel (VGIC) superfamily members contain six-transmembrane segments in which the first four form a voltage-sensing domain (VSD) and the last two form the pore domain (PD). Studies of potassium channels from the VGIC superfamily together with identification of voltage-sensor only proteins have suggested that the VSD and the PD can fold independently. read moreRead Full Story

Linear rate-equilibrium (RE) relations, also known as linear free energy relations, are widely observed in chemical reactions, including protein folding, enzymatic catalysis, and channel gating. Despite the widespread occurrence of linear RE relations, the principles underlying the linear relation between changes in activation and equilibrium energy in macromolecular reactions remain enigmatic. read moreRead Full Story

Dimeric ligands can be potent inhibitors of protein-protein or enzyme-substrate interactions. They have increased affinity and specificity toward their targets due to their ability to bind two binding sites simultaneously and are therefore attractive in drug design. However, few studies have addressed the kinetic mechanism of interaction of such bivalent ligands. read moreRead Full Story

Cytochrome c oxidase is the terminal enzyme of the respiratory chain that is responsible for biological energy conversion in mitochondria and aerobic bacteria. The membrane-bound enzyme converts free energy from oxygen reduction to an electrochemical proton gradient by functioning as a redox-coupled proton pump. read moreRead Full Story

Delivery of macromolecules into cells and tissues such as skin is a major challenge. This obstacle poses a particular challenge for the delivery of siRNA where cellular and tissue level transport barriers need to be overcome. read moreRead Full Story

The proposal that enzymatic catalysis is due to conformational fluctuations has been previously promoted by means of indirect considerations. However, recent works have focused on cases where the relevant motions have components toward distinct conformational regions, whose population could be manipulated by mutations. read moreRead Full Story

Protein release factor 3 (RF3), a guanosine triphosphatase, binds to ribosome after release of the nascent peptide and promotes dissociation of the class I release factors during the termination of protein synthesis. read moreRead Full Story

Delivery of macromolecules into cells and tissues such as skin is a major challenge. This obstacle poses a particular challenge for the delivery of siRNA where cellular and tissue level transport barriers need to be overcome. read moreRead Full Story