Peptides permeases

Fig. 6.9. Rationale for the design of peptidic prodrugs (6.15) of 5-fluorouracil (6.17) targeting microbial peptides permeases and peptidases [37]...

Because of their extra external membrane. Gram-negative bacteria are accessible to fewer anti-bacterials than Gram-positive organisms. A new attempt to remedy this situation has produced alafosfalin (3.50) which makes use of a peptide permease in this outer membrane to transport the drug into the cell where it is hydrolysed to L-aminoethylphosphonic acid, a potent inhibitor of L-alanine racemase. The normal product of this enzyme, D-alanine, is an... 

Two are hydrophobic intrinsic membrane domains, each with six membrane-spanning helices and two are peripheral membrane ATP binding domains. All four domains may be in a single peptide chain, as in CFTR, or they may be separate smaller proteins as in bacterial periplasmic permeases.431 446... 

The plasma membrane of many bacteria contains numerous permeases that belong to the ABC superfamily. These proteins use the energy released by hydrolysis of ATP to transport specific amino acids, sugars, vitamins, or even peptides into the cell. Since bacteria frequently grow in soil or pond water where the concentration of nutrients is low, these... 

Manson, M.D., Blank, V., Brade, G. and Higgins, C.F. (1986). Peptide chemotaxis in E. coli involves the Tap signal transducer and the dipeptide permease. Nature (London) 321, 253-256. 

Figure 1.3. Diagram of the proteolytic systems of lactic acid bacteria, (a) Extracellular components PrtP, cell-envelope proteinase PrtM, proteinase maduration protein Opp, oligopetide permease DtpT, the ion linked trasnsporter for di-and tripeptides and Opt, the ABC transporter for peptides, (b) Intracelullar components pool of about 20-25 peptidases, including general (PepN, PepC) and specific (PepX, PepQ) peptidases, and amino acid catabolic enzymes (carboxylases, aminotransferases, etc.).

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