Dihydropteroate synthetase inhibitor
Encyclopedia
A dihydropteroate synthetase inhibitor is a drug that inhibits the action of dihydropteroate synthetase
. Most are sulfonamide
s.
In bacteria, antibacterial sulfonamides act as competitive inhibitors of the enzyme dihydropteroate synthetase
, DHPS. DHPS catalyses the conversion of PABA (para-aminobenzoate) to dihydropteroate, a key step in folate synthesis. Folate is necessary for the cell to synthesize nucleic acid
s (nucleic acids are essential building blocks of DNA
and RNA
), and in its absence cells will be unable to divide. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect.
s, and shigellosis
.
Dihydropteroate synthetase
Dihydropteroate synthetase is an enzyme classified under . It produces dihydropteroate in bacteria, but it is not expressed in most eukaryotes including humans...
. Most are sulfonamide
Sulfonamide (medicine)
Sulfonamide or sulphonamide is the basis of several groups of drugs. The original antibacterial sulfonamides are synthetic antimicrobial agents that contain the sulfonamide group. Some sulfonamides are also devoid of antibacterial activity, e.g., the anticonvulsant sultiame...
s.
Dihydropteroate synthetase
Dihydropteroate synthetase is an enzyme classified under . It produces dihydropteroate in bacteria, but it is not expressed in most eukaryotes including humans...
, DHPS. DHPS catalyses the conversion of PABA (para-aminobenzoate) to dihydropteroate, a key step in folate synthesis. Folate is necessary for the cell to synthesize nucleic acid
Nucleic acid
Nucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...
s (nucleic acids are essential building blocks of DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
and RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
), and in its absence cells will be unable to divide. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect.
Uses
Folate is not synthesized in mammalian cells, but is instead a dietary requirement. This explains the selective toxicity to bacterial cells of these drugs. These antibiotics are used to treat pneumocystis jiroveci pneumonia, urinary tract infectionUrinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
s, and shigellosis
Shigellosis
Shigellosis, also known as bacillary dysentery or Marlow Syndrome, in its most severe manifestation, is a foodborne illness caused by infection by bacteria of the genus Shigella. Shigellosis rarely occurs in animals other than humans and other primates like monkeys and chimpanzees...
.