Proteomic characterization of the acid-insoluble fraction of whole saliva from preterm human newborns
JOURNAL OF PROTEOMICS
Authors: Arba, Morena; Iavarone, Federica; Vincenzoni, Federica; Manconi, Barbara; Vento, Giovanni; Tirone, Chiara; Cabras, Tiziana; Castagnola, Massimo; Messana, Irene; Sanna, Maria Teresa
Abstract
The acid-insoluble salivary proteome obtained by addition of TFA to whole human saliva from adults, preterm and at-term newborns has been analysed by 2-DE in order to evidence differences among the three groups, and integrate data previously obtained on the acid-soluble fraction. 2-DE spots differentially expressed among the three groups were submitted to in-gel tryptic digestion and the peptide mixtures analysed by high resolution HPLC-ESI-MS/MS. By this strategy, we identified 3 over-expressed proteins in at-term newborns with respect to preterm newborns and adults (BPI fold-containing family A member 1, annexin A1, and keratin type 1 cytoskeletal 13), and several over-expressed proteins in adults (fatty acid-binding protein, 5100 A6, S100 A7, S100 A9, prolactin-inducible protein, Ig kappa chain, cystatin SN, cystatin S/SA and alpha-amylase 1). Four spots, already detected but not characterized by other authors in human saliva 2-DE, were attributed to different protein species of S100 A9 (long-type and long-type monophosphorylated, short-type and short-type monophosphorylated) by MS/MS analysis of tryptic peptides and sequential staining of 2-DE gels with Pro-Q Diamond, for specific detection of phosphoproteins, and total protein SYPRO Ruby stain. Significance: Differential protein expression analysis of the acid insoluble fraction of saliva from preterm, at-term newborns and adults has been performed in this study by coupling 2-DE analysis and high-resolution tandem mass spectrometry in order to complete the information previously obtained by top-down LC-MS only on the acid-soluble proteome. Several proteins identified in the acid insoluble fraction of both preterm newborn and adult saliva are not of glandular origin, being only prolactin-inducible protein, salivary cystatins, alpha-amylase and polymeric immunoglobulin receptor exclusive of salivary glands. Three proteins resulted increased in at-term newborns with respect to preterm newborns and adults: BPI fold containing family A member 1, two proteoforms of annexin A1 and keratin type 1 cytoskeletal 13, while several proteins were significantly increased in adults. (C) 2016 Elsevier B.V. All rights reserved.
Metal limitation and toxicity at the interface between host and pathogen
FEMS MICROBIOLOGY REVIEWS
Authors: Becker, Kyle W.; Skaar, Eric P.
Abstract
Metals are required cofactors for numerous fundamental processes that are essential to both pathogen and host. They are coordinated in enzymes responsible for DNA replication and transcription, relief from oxidative stress, and cellular respiration. However, excess transition metals can be toxic due to their ability to cause spontaneous, redox cycling and disrupt normal metabolic processes. Vertebrates have evolved intricate mechanisms to limit the availability of some crucial metals while concurrently flooding sites of infection with antimicrobial concentrations of other metals. To compete for limited metal within the host while simultaneously preventing metal toxicity, pathogens have developed a series of metal regulatory, acquisition, and efflux systems. This review will cover the mechanisms by which pathogenic bacteria recognize and respond to host-induced metal scarcity and toxicity.