In our previous work we reported that HIV Tat and 6 cysteine rich peptides of Tat induce tumor necrosis factor-related apoptosis-induced ligand (TRAIL) in human monocytes (Yang et al., 2003). Here our results showed t...In our previous work we reported that HIV Tat and 6 cysteine rich peptides of Tat induce tumor necrosis factor-related apoptosis-induced ligand (TRAIL) in human monocytes (Yang et al., 2003). Here our results showed that HIV Tat and Tat cysteine rich peptide increase CCR5 expression in human monocytes, and this activity is inhibited by rabbit anti-Tat. Boiled Tat does not increase CCR5 expression in monocytes. These results provide insight into a new mechanism by which HIV Tat plays a key role in the pathogenesis of HIV-1 infection.展开更多
In this work, the role of the disulfide bridges in the maintenance of the secondary structure of the antimicrobial peptides androctonin, poly-phemusin-I, and thanatin is analyzed on the basis of their structural chara...In this work, the role of the disulfide bridges in the maintenance of the secondary structure of the antimicrobial peptides androctonin, poly-phemusin-I, and thanatin is analyzed on the basis of their structural characteristics and of three of their respective mutants, andry4, poly4, and thany2, in which all the cysteine residues have been replaced with tyrosine residues. The absence of the disulfide bridges in andry4, poly4, and thany2 seems to be compensated by an overall enforcement of the original hydrogen bonds and by extra attractive interactions between the aromatic rings of the tyrosine residues. In spite of the mutations, the original β-hairpin structures are maintained in the three mutants, but the best conformational similarities are found for the androctonin/andry4 pair.展开更多
文摘In our previous work we reported that HIV Tat and 6 cysteine rich peptides of Tat induce tumor necrosis factor-related apoptosis-induced ligand (TRAIL) in human monocytes (Yang et al., 2003). Here our results showed that HIV Tat and Tat cysteine rich peptide increase CCR5 expression in human monocytes, and this activity is inhibited by rabbit anti-Tat. Boiled Tat does not increase CCR5 expression in monocytes. These results provide insight into a new mechanism by which HIV Tat plays a key role in the pathogenesis of HIV-1 infection.
基金Fundacao de Amparo a Pesquisa do Estado de Sao Paulo(FAPESP)for financial support.
文摘In this work, the role of the disulfide bridges in the maintenance of the secondary structure of the antimicrobial peptides androctonin, poly-phemusin-I, and thanatin is analyzed on the basis of their structural characteristics and of three of their respective mutants, andry4, poly4, and thany2, in which all the cysteine residues have been replaced with tyrosine residues. The absence of the disulfide bridges in andry4, poly4, and thany2 seems to be compensated by an overall enforcement of the original hydrogen bonds and by extra attractive interactions between the aromatic rings of the tyrosine residues. In spite of the mutations, the original β-hairpin structures are maintained in the three mutants, but the best conformational similarities are found for the androctonin/andry4 pair.
