title: A mammalian peptidoglycan recognition protein with N-acetylmuramoyl-L-alanine amidase activity.
abstract: The family of peptidoglycan recognition proteins (PGRPs) is conserved from insects to mammals. Recently, Drosophila PGRP-SC1B was demonstrated to be an N-acetylmuramoyl-L-alanine amidase (NAMLAA), an enzyme that cleaves the lactylamide bond between muramic acid and the peptide chain in peptidoglycan (PGN). We now show an M x mPGRP-L mRNA to be expressed in the liver. The recombinant M x mPGRP-L protein has NAMLAA activity and degrades PGN from both Escherichia coli and Staphylococcus aureus; however, the Gram-positive PGN was a better substrate after lysozyme treatment. The activity of M x mPGRP-L was further analysed using Bordetella pertussis tracheal toxin as a substrate. Cleavage products were separated on HPLC and identified using mass spectrometry. From these results we conclude that M x mPGRP-L has activity and other properties identifying it as the NAMLAA protein present in mammalian sera.
authors.affiliation: Department of Microbiology, Stockholm University, S-106 91 Stockholm, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Gelius
authors.forename: Carina
authors.initials: C
authors.lastname: Persson
authors.forename: Jenny
authors.initials: J
authors.lastname: Karlsson
authors.forename: Håkan
authors.initials: H
authors.lastname: Steiner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D008099:Liver / Q000201:enzymology* / Q000382:microbiology; D051379:Mice; D008969:Molecular Sequence Data; D009113:Muramidase / Q000494:pharmacology; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism*; D010457:Peptidoglycan / Q000737:chemistry*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013211:Staphylococcus aureus / Q000378:metabolism; D013997:Time Factors
chemical_list: D002352:Carrier Proteins; D010457:Peptidoglycan; D011994:Recombinant Proteins; C118897:peptidoglycan recognition protein; D009113:Muramidase; D009238:N-Acetylmuramoyl-L-alanine Amidase