title: Penicillin-degrading activities of peptides from pneumococcal penicillin-binding proteins.
abstract: Trypsin treatment of native penicillin-binding proteins (PBPs) 1a, 2b and 3 from Streptococcus pneumoniae resulted in the formation of stable peptides containing the beta-lactam-binding site with molecular masses ranging from 26 kDa to 36 kDa. Whereas the PBP 1a peptide (Ia) was enzymatically rather unstable, the PBP 2b peptide (IIb) and the PBP 3 peptide (III) were able to bind and release beta-lactams with similar rates compared to the intact PBP, the turnover rate of fragment II b was even twice as fast as that observed with PBP 2b. Analysis of the turnover products by thin-layer chromatography revealed that PBP 2b and 3 produced penicilloic acid as well as phenylacetylglycine. On the other hand, with the corresponding tryptic fragments only the hydrolysis product penicilloic acid was obtained.
authors.affiliation: Abteilung Trautner, Max-Planck-Institut für Molekulare Genetik, Berlin.
authors.forename: H
authors.initials: H
authors.lastname: Ellerbrok
authors.forename: R
authors.initials: R
authors.lastname: Hakenbeck
mesh_terms: D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000378:metabolism*; D006602:Hexosyltransferases; D007700:Kinetics; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism*; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D010458:Peptidyl Transferases; D011485:Protein Binding; D013296:Streptococcus pneumoniae / Q000378:metabolism*; D014357:Trypsin
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010446:Peptide Fragments; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D014357:Trypsin