A novel β-hairpin peptide derived from the ARC repressor selectively interacts with the major groove of B-DNA

Discovery of Polyvalent Myovirus (vB_STM-2) Phage as a Natural Antimicrobial System to Lysis and Biofilm Removal of Salmonella Typhimurium Isolates from Various Food Sources

“…The mechanism by which bacteria can resist the action of antibiotics may be the over-expression of efflux pumps that lead to the active efflux of antibiotics from the bacterial cell and restrict the antibiotics to their target sites by decreasing the selective permeability of the bacterial cell wall. In addition, bacteria may produce target enzymes to circumvent the drug's antibacterial activity [73][74][75]. Salmonella Typhimurium (ST-4) was used to isolate phage, as it is the strongest isolate for biofilm production.…”

New Teixobactin Analogues with a Total Lactam Ring

“…The standard SPPS procedure was followed, using 3 equiv of each amino acid for each coupling and HBTU (3 equiv), HOBt (3 equiv), and DIPEA (6 equiv) dissolved in 4 mL of DMF as the coupling mixture. , 120 mg of 2-CT-Cl resin (1 equiv) was weighed into a syringe for manual solid phase synthesis and swelled in DCM (8 mL) for 1 h with an automatic shaker. For the first coupling, 5 mL of a DCM solution containing the first amino acid and DIPEA was added to the resin and shaken overnight.…”

“…Furthermore, teixobactin interacts as β-sheet dimer with cell wall membrane components, thus generating two cavities comprising the C -terminal cycle and N -terminus acting as receptor for pyrophosphate groups via hydrogen bonding . As observed by the X-ray crystallographic structure of teixobactin analogues, a lactam bridge in place of a lactone may improve the interaction with lipids II and III; however, ring expansion resulted in analogues with very poor activity. , The solid state NMR work reported by Shukla and co-workers helps to clarify the importance of the relative stereochemistry and structural features of teixobactin: The use of a labeled analogue reveals the ability of this molecule to form a large cluster on the membrane surface by oligomerization of lipid II-binding teixobactin. − This molecule assumes a β-sheet form in which the critical sequence of d - and l -amino acids allows separation of hydrophobic and hydrophilic side chains located at the same side of the β-sheet, a common behavior of diverse naturally occurring peptides. − The peptide head containing ring interacts with N -acetyl muramic acid and to a minor extent with N -acetyl-glucosamine; the tail is anchored on the membrane surface by two isoleucines. In this way teixobactin significantly perturbs the bacterial membrane lipids and cell wall biosynthesis. , …”

Hydroalcoholic extract: A potential source from Azadirachta indica a Juss flower for DNA and BSA binding, scavenging, fungicidal, and larvicidal activities

“…Scientists have been more interested in DNA minor grooves addressed by small compounds than interaction with the major groove over the years, owing mostly to biologically important macromolecules identified in the 1970s (Dervan, 2001; Dervan & B€urli, 1999; Johnson et al., 1996). Some examples that target the major groove binding are chromomycin, actinomycin D, distamycin, netropsin, and Hoechst 33258 (Gao et al., 1992; Guan et al., 1993; Kamitori & Takusagawa, 1992; Stefanucci et al., 2021). But many macromolecules, like proteins, are bounded mainly to through hydrogen bonding found in the main groove, suggesting that the major groove would be a more appealing target for drugs (Mamoon et al., 2002; Simonsson et al., 1998; Singh & Lambowitz, 2001).…”