title: Large protein analysis of Staphylococcus aureus and Escherichia coli by MALDI TOF mass spectrometry using amoxicillin functionalized magnetic nanoparticles.
abstract: Bacteria or their protein and peptide entity enrichment using biomolecules-functionalized magnetic nanoparticles, and analysis by matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) is a promising technique to analyze microorganisms. High and low molecular weight proteins like penicillin-binding proteins are responsible for final step synthesis of peptidoglycan biosynthesis; those are the target of lactam antibiotics. In this paper, we synthesized magnetic nanoparticles (mag-NPs) and further modified them with 3-aminopropyltriethoxysilane, and then the β-lactam antibiotic amoxicillin was covalently linked to their surface. β-Lactam group attributes as penicillin binding proteins (PBPs) in bacteria. Staphylococcus aureus and Escherichia coli were used as model bacteria for enrichment based on the β-lactam affinity of magnetic nanoparticles, and then the bacteria were easily separated by an external magnet. Several high molecular weight penicillin binding proteins (PBPs) were detected by MALDI MS containing 10(4) and 10(3) colony-forming unit (cfu) per milileter (mL) of S. aureus and E. coli, respectively. In the case of E. coli, higher molecular weight PBPs were observed at 20 to 55 kDa in MALDI mass spectra. However, S. aureus bacteria resulted with femAB operon-based proteins, with molecular weight of 49570.4 Da, by MALDI MS after using amoxicillin functionalized-mag-NPs. The current approach provides an effective bacteria detection and preconcentration method that has high potential in the near future for fast and sensitive diagnosis of pathogenic bacteria infection. Graphical Abstract Schematic for large proteins analysis by MALDI TOF MS (a) mag-NPs and bacterial interaction (b) Penicillin binding proteins trapping by Amox-mag-NPs.
authors: Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, 70, Lien-Hai Road, Kaohsiung, 80424, Taiwan.|Department of Chemistry, Faculty of Science, Jazan University, P.O. Box 2097, Jazan, 82621, Saudi Arabia.
authors: Nazim
authors: N
authors: Hasan
authors: Water Quality Office, Public Utilities Board, 82 Toh Guan Road East, Water Hub, # C4-03, Singapore, 608576, Singapore.
authors: Zhongxian
authors: Z
authors: Guo
authors: Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, 70, Lien-Hai Road, Kaohsiung, 80424, Taiwan. hwu@faculty.nsysu.edu.tw.|School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, 807, Taiwan. hwu@faculty.nsysu.edu.tw.|Institute of Medical Science and Technology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung, 80424, Taiwan. hwu@faculty.nsysu.edu.tw.|Marine Biotechnology, National Sun Yat-Sen University and Academia Sinica, Kaohsiung, 80424, Taiwan. hwu@faculty.nsysu.edu.tw.
authors: Hui-Fen
authors: HF
authors: Wu
mesh_terms: D000658:Amoxicillin / Q000737:chemistry*; D001426:Bacterial Proteins / Q000032:analysis* / Q000302:isolation & purification; D004926:Escherichia coli / Q000737:chemistry* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D058185:Magnetite Nanoparticles; D000658:Amoxicillin
keywords: Amoxicillin; Bacteria enrichment; Magnetite nanoparticles; Matrix assisted laser desorption/ionization time of flight mass spectrometry; β-Lactam affinity