Bionanoconjugation for Proteomics applications — An overview

Metal-Organic Frameworks for Preserving the Functionality of Plasmonic Nanosensors

Preserving the functionality of nanosensors is critical for their reliable performance under harsh environmental conditions. Biofunctionalized plasmonic nanostructures are an important class of bionanoconjugates for biosensing, bioimaging, and nanotherapeutics. Plasmonic nanostructures and biomolecules exhibit poor thermal stability over time. Here, we report a class of metal-organic framework, zeolitic imidazolate framework-8 (ZIF-8), as a protective coating for preserving plasmonic nanostructures and plasmonic bionanoconjugates at elevated temperature. Gold nanobipyramids (AuNBPs) with sharp tips are attractive plasmonic nanotransducers with high sensitivity but are prone to structural change and loss of sensitivity. This work reports the first observation that ZIF-8 can preserve the structure of AuNBPs and their corresponding strong electromagnetic field enhancement and high refractive index sensitivity. In addition, ZIF-8 coating enables nearly 100% retention of biorecognition capability of antibodies immobilized on the AuNBP surface after exposure to 60 °C for 48 h. The efficacy, versatility, and facile implementation of ZIF-8 coating offer great promise for the preservation of nanosensors.

Proteomic studies with a novel nano-magnetic chelating system to capture metalloproteins and its application in the preliminary study of monocyte and macrophage sub-secretome

A new chelating chromatography method was developed based in the use of magnetic iron oxide nanoparticles functionalized with EDTA-TMS ((N-(trimethoxysilylpropyl)ethylenediaminetriacetate trisodium salt). These particles combine a high surface area, biocompatibility and magnetic removal from solution, with the chelating affinity towards metal ions. The particles were used to selectively capture metallo-dependant proteins in secretome obtained from human monocytes and mouse macrophages. Secreted metallo-dependant proteins are highly important sources of information since they are involved in several pathological processes. The identification of secreted proteins involved in these processes is highly important for diagnosis or monitoring the progression of a disease. In this multiple-approach study it was possible to not only selectively capture several secreted metallo-dependant proteins, but also to significantly avoid masking proteins such as the highly abundant albumin form the fetal bovine serum used to supplement the cell culture medium. Overall, the magnetic nanoparticle-based chelating chromatography method developed here has proved to be a sensitive, low cost, and a quick tool for sample treatment in order to selectively enrich metalloproteins while overcoming the contamination of highly abundant proteins.

Bovine glutamate dehydrogenase immobilization on magnetic nanoparticles: conformational changes and catalysis

Glutamate dehydrogenase (GDH) was immobilized on different supports and systematically investigated in order to provide a better understanding of the immobilization effects on the catalysis of multimeric enzymes.

Toward the definition of a peptidome signature and protease profile in chronic periodontitis

PURPOSE

Chronic periodontitis (CP) is a complex immuno-inflammatory disease that results from preestablished gingivitis. We investigated potential differences in salivary peptidome in health and CP.

EXPERIMENTAL DESIGN

Saliva was collected from nine CP patients and ten healthy subjects, from which five CP and five healthy were enriched following endoProteoFASP approach, separated and identified by nanoHPLC-MALDI-TOF/TOF. Protease prediction was carried out in silico with Proteasix. Parallel gelatin and collagen (I) zymographies were performed to study proteolytic activity in CP.

RESULTS

An association of CP with increased gelatinolytic and collagenolytic activity was observed, which is mainly attributed to metalloproteases, remarkably MMP9. Protease prediction revealed distinct protease profiles in CP and in health. Peptidomic data corroborated the inflammatory status, and demonstrated that intact histatin 1 may play an important role in the defense response against oral pathogens. The application of the endoProteoFASP approach to study the salivary peptidome of CP subjects resulted in the identification of eight surrogate peptide markers, which may be used in multiplex to identify CP. These peptides belong to acidic PRP and to P-B peptide. Particularly, P-B peptide fragments exhibited domains with potential predicted antimicrobial activity, corroborating an antimicrobial function.

CONCLUSIONS AND CLINICAL RELEVANCE

The comparison between the salivary peptidome obtained by control and CP samples showed a specific association of eight peptides to CP, with remarkable predicted antimicrobial activity, which should be further validated in studies with large number of subjects.

Magnetic chelating nanoprobes for enrichment and selective recovery of metalloproteases from human saliva

Magnetic nanoparticles effective in the selective recovery of metalloproteases from human saliva were fabricated by surface modification of Fe₃O₄@SiO₂nanoparticles with EDTA-TMS.