Chem167_L18_Jun4_final

Transpepdase enzyme which is involved in the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: y constructed in cytoplasm • Constructed from 2 sugars (NAM, NAG) and a pep*de chain • Transported across cell membrane and completed • Linked to growing cell wall by enzyme (transglycosida*on) • Final cross- linking reac*on catalysed by transpep*dase enzymes PENICILLINS • An#bacterial agents which inhibit bacterial cell wall synthesis • Discovered by Fleming from a fungal colony (1928) • Shown to be non toxic and an#bacterial • Isolated and purified by Florey and Chain (1938) • First successful clinical trial (1941) • Produced by large scale fermenta#on (1944) • Structure established by X- ray crystallography (1945) • Full synthesis developed by Sheehan (1957) • Isola#on of 6- APA by Beechams (1958- 60) - development of semi- synthe#c penicillins • Discovery of clavulanic acid and β- lactamase inhibitors Beta lactam an*bio*cs Broad class of an#bio#cs Agents that contain a beta- lactam nucleus Includes penicillin (1) deriva#ves, cephalosporins (2), monobactams, & carbapenems Mechanism of ac#on • Penicillins inhibit a bacterial enzyme called the transpep#dase enzyme which is involved in the synthesis of the bacterial cell wall • The β- lactam ring is involved in the mechanism of inhibi#on • Penicillin becomes covalently linked to the enzyme’s ac#ve site leading to irreversible inhibi#on O C HH N S R N Nu O H Me Me O Enz C CO2H HH N R Enz-Nu -H O H S N Me Me O H CO2H C HH N H R O C HN Nu-Enz S Me Me CO2H • Covalent bond formed to transpep#dase enzyme • Irreversible inhibi#on Mechanism of ac#on - bacterial cell wall synthesis NAM L- Ala D- Glu L- Lys NAG NAM L- Ala D- Glu L- Lys Bond forma#on inhibited by...
View Full Document

This note was uploaded on 01/15/2014 for the course CHEM 167 taught by Professor Amaro during the Winter '13 term at UCSD.

Ask a homework question - tutors are online