The active core in a triazole peptide dual-site antagonist of HIV-1 gp120.

In an effort to identify broadly active inhibitors of HIV-1 entry into host cells, we previously reported a family of dodecamer triazole-peptide conjugates with nanomolar affinity for the viral surface protein gp120. This peptide class exhibits potent antiviral activity and the capacity to simultaneously inhibit interaction of the viral envelope protein with both CD4 and co-receptor. In this investigation, we minimized the structural complexity of the lead triazole inhibitor HNG-156 (peptide 1) to explore the limits of the pharmacophore that enables dual antagonism and to improve opportunities for peptidomimetic design.

Proximal influences in two-on-two globins: effect of the Ala69Ser replacement on Synechocystis sp. PCC 6803 hemoglobin.

The cyanobacterium Synechocystis sp. PCC 6803 (S6803) expresses a two-on-two globin in which His46 (distal side) and His70 (proximal) function as heme iron axial ligands. His46 can be displaced by O2, CO, and CN-, among others, whereas His70 is not labile under native conditions.

Structural properties of cyanobacterial hemoglobins: the unusual heme-protein cross-link of Synechocystis sp. PCC 6803 Hb and Synechococcus sp. PCC 7002 Hb.

The truncated hemoglobins from Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002 ligate the heme iron with two axial histidines (HisF8 and HisE10).

Characterization of the heme-histidine cross-link in cyanobacterial hemoglobins from Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002.

The recombinant product of the hemoglobin gene of the cyanobacterium Synechocystis sp. PCC 6803 forms spontaneously a covalent bond linking one of the heme vinyl groups to a histidine located in the C-terminal helix (His117, or H16). The present report describes the (1)H, (15)N, and (13)C NMR spectroscopy experiments demonstrating that the recombinant hemoglobin from the cyanobacterium Synechococcus sp.