Periodate increases the sensitivity of sarcoplasmic reticulum to phospholipase A2

Hyper-crosslinked peptidoglycan was synthesized in vitro by purified penicillin-binding protein 1A of Escherichia coli. The peptidoglycan formed was crosslinked up to 39%. About half the crosslinks were novel three-handed crossbridges whereas the other half were two-handed crossbridges that are the major constituents of normally crosslinked peptidoglycan of E. coli. The structure of the three-handed crossbridge constructed among three peptide side-chains of -l-alanyl-d-glutamyl-meso-diaminopimelyl-d-alanyl-d-alanine was deduced from several criteria. Probably penicillin-binding protein 1A is responsible for hyper-crosslinking of E. coli peptidoglycan in vivo.