RESUMO
Novel hierarchical porous carbon materials (HPCs) were fabricated via a reactive template-induced in situ hypercrosslinking procedure. The effects of carbonization conditions on the microstructure and morphology of HPCs were investigated, and the adsorption of methylene blue (MB) on HPCs was explored. The as-prepared HPCs has a hierarchical micro-, meso- and macropore structure, which results from the overlap of hollow nanospheres possessing microporous shells and macroporous cavities. The carbonization temperature, carbonization time and carbonization heating rate played important roles in tailoring the nanostructures of HPCs. The BET specific surface area and micropore specific surface area can reach 2388 m2 g-1 and 1892 m2 g-1, respectively. Benefitting from the well-developed pore structure, the MB removal efficiency can exceed 99% under optimized conditions. The adsorption kinetics and thermodynamics can be well described by a pseudo-second-order model and Langmuir model, respectively. Furthermore, such adsorption was characterized by a spontaneous endothermic process.
RESUMO
HIV entry is mediated by the envelope glycoproteins gp120 and gp41. The gp41 subunit contains several functional domains: the N-terminal heptad repeat (NHR) domains fold a triple stranded coiled-coil forming a meta-stable prefusion intermediate. The C-terminal heptad repeat (CHR) subsequently folds onto the hydrophobic grooves of the NHR coiled-coil to form a stable 6-helix bundle, which juxtaposes the viral and cellular membranes for fusion. A conserved salt bridge between Lys(574) in NHR and Asp(632) in CHR plays an essential role in the formation of the six-helix bundle. A multi-functional peptide inhibitor for anti-HIV derived from the CHR of gp41 has been designed. It bears a cholesterol group (Chol) at the C-terminal through which the inhibitor can anchor in the cell membrane, and carries an isothiocyanate (NCS) group at the side chain of Asp(632) through which the inhibitor can bind to target covalently at Lys(574) in NHR. The dual functionalized peptide (NCS-C34-Chol) shows high antiviral activity in vitro and in vivo. The inhibitor reacts specifically and rapidly to NHR from gp41. In addition, it exhibits better stability under the digestion of the Proteinase K than C34 and T20.