Netropsin (also termed congocidine or sinanomycin) is a

polyamide A polyamide is a polymer with repeating units linked by amide bonds. Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made throug ...

with

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

and antiviral activity. Netropsin was discovered by Finlay ''et al.'', and first isolated from the actinobacterium '' Streptomyces netropsis''. It belongs to the class of pyrrole-amidine

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

DNA binding properties

Netropsin binds to the minor groove of AT-rich sequences of double stranded

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

. In contrast, netropsin does not bind single stranded DNA or double stranded RNA. Crystallographic structures of DNA-bound Netropsin have been obtained and elucidate details of how the drug binds in the minor groove. In the bound structure, the drug makes hydrogen bonding interactions with four subsequent base pairs of the DNA duplex, locally displacing the water molecules of the spine of hydration. Using gel mobility and analytical ultracentrifugation, it was shown that Netropsin binding to DNA increases the twist per base by similar to 9˚ per molecule bound. Thus, it removes supercoils when interacting with positively supercoiled DNA and introduces (additional) negative supercoils when binding to relaxed or negatively supercoiled DNA. Netropsin's effect on supercoiled DNA was observed in detail on single molecules using a magnetic tweezers.

Antibiotic properties

It has been shown that Netropsin is active both against

Gram-positive bacteria In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain ...

and

Gram-negative bacteria Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelo ...

.C. Zimmer and U. Wähnert, ''Prog. Biophys. Molec. Biol.'' 47 31-112 (1986)

References

{{Reflist Amidines Guanidines Antibiotics DNA-binding substances Imidazoles

DNA binding properties

Antibiotic properties

See also

References