Site-Specific Fluorescent Labeling of the Cysteine-Rich Toxin, DkTx, for TRPV1 Ion Channel Imaging and Membrane Binding Studies.

Peptide toxins secreted by venomous animals bind to mammalian ion channel proteins and modulate their function. The high specificity of these toxins for their target ion channels enables them to serve as powerful tools for ion channel biology. Toxins labeled with fluorescent dyes are employed for the cellular imaging of channels and also for studying toxin-channel and toxin-membrane interactions.

Tertiary-Butylbenzene Functionalization as a Strategy for β-Sheet Polypeptides.

β-Sheet forming polypeptides are one of the least explored synthetic systems due to their uncontrolled precipitation in the ring-opening polymerization (ROP) synthetic methodology. Here, a new -butylbenzene functionalization approach is introduced to overcome this limitation by sterically controlling the propagating polymer chains, and homogeneous polymerization with good control over chain growth was accomplished. New bulky -carboxyanhydride monomers were designed having -butylbenzene pendant by multistep organic synthesis, and N-heterocyclic carbene was explored as a catalyst to make high-molecular-weight and narrow polydisperse soluble polypeptides.

Rapid and reversible hydrazone bioconjugation in cells without the use of extraneous catalysts.

The amenability of hydrazone linkages to disassemble via either hydrolysis in mildly acidic aqueous solutions or transimination upon treatment with amine nucleophiles renders them extremely attractive for applications in chemical biology, drug delivery and materials science. Unfortunately, however, the use of hydrazones is hampered by the extremely slow intrinsic rates of their formation from their hydrazine and carbonyl precursors. Consequently, hydrazone formation is typically performed in the presence of a large excess of cytotoxic aniline-based nucleophilic catalysts, rendering hydrazones unsuitable for biological applications that entail their formation in cells.