UPLC-MS is a commonly used technique to first separate complex samples and subsequently quantify molecules of interest. Herein we describe the use of UPLC-MS using an amide stationary phase to quantify non-derivatized amino acids extracted from fingerprints. As detector either a triple-quadrupole MS/MS or a TOF-MS detector was used. This method allows for a simple and fast sample preparation, which facilitates the analysis of large amounts of samples.
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The amino acid profile obtained from a fingerprint may provide valuable information on its donor. Unfortunately, the collection of chemicals from the fingerprint is often destructive to the fingerprint ridge detail. Herein we detail the use of cross-linkable solutions of dextran-methacrylate to form hydrogels capable of collecting amino acids from surfaces followed by extraction and quantification with UPLC-MS. This method allows for the amino acid profile analysis of fingerprints while allowing for their increased visualization at a later stage using the standard method of cyanoacrylate fuming followed by basic-yellow dyeing.
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OBJECTIVES: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid supplementation compared to placebo on muscle mass and strength in older adults by combining the results from published trials in a meta-analysis and pooled individual participant data analysis.DESIGN: We searched Medline and Cochrane databases and performed a meta-analysis on eight available trials on the effect of protein or amino acid supplementation on muscle mass and strength in older adults. Furthermore, we pooled individual data of six of these randomized double-blind placebo-controlled trials. The main outcomes were change in lean body mass and change in muscle strength for both the meta-analysis and the pooled analysis.RESULTS: The meta-analysis of eight studies (n=557) showed no significant positive effects of protein or amino acid supplementation on lean body mass (mean difference: 0.014 kg: 95% CI -0.152; 0.18), leg press strength (mean difference: 2.26 kg: 95% CI -0.56; 5.08), leg extension strength (mean difference: 0.75 kg: 95% CI: -1.96, 3.47) or handgrip strength (mean difference: -0.002 kg: 95% CI -0.182; 0.179). Likewise, the pooled analysis showed no significant difference between protein and placebo treatment on lean body mass (n=412: p=0.78), leg press strength (n=121: p=0.50), leg extension strength (n=121: p=0.16) and handgrip strength (n=318: p=0.37).CONCLUSIONS: There is currently no evidence to suggest that protein or amino acid supplementation without concomitant nutritional or exercise interventions increases muscle mass or strength in predominantly healthy elderly people.
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De postdoc kandidaat, Tanja Moerdijk, zal op structurele wijze de reeds door haar gemaakte verbinding tussen het lectoraat Marine Biobased Specialties (MBBS) en de opleiding Chemie van HZ University of Applied Sciences verder uitbouwen en bestendigen. Streven is dat het MBBS Bioprospecten onderzoek zichtbaar is in alle studiejaren van de opleiding Chemie en praktijkcasuïstiek structureel ingebracht wordt in het curriculum. De postdoc is daarom betrokken bij alle studiejaren van de opleiding. Zij zal de ontwikkeling van een geïntegreerde onderzoeksleerlijn in het Chemie curriculum coördineren, welke gevoed wordt vanuit het MBBS onderzoeksprogramma waardoor inbedding van onderzoek in de opleiding wordt geborgd. Verdieping, overdracht en deling van kennis met betrekking tot het chemische smaak- en textuurprofiel van zeewier zal uitgevoerd worden door zowel postdoc als studenten door te participeren in het uitvoeren van praktijkgericht onderzoek aan (polymeer)moleculen uit zeewier in samenwerking met de zeewierproducenten. Deze kennis zal uiteindelijk bijdragen aan een duurzame productie en verwerking van zeewier tot eindproducten voor de consument. Omdat het onderwerp breed en maatschappelijke relevant is, creëert het bovendien de mogelijkheid voor andere opleidingen en onderzoeksgroepen om de verbinding eenvoudig te kunnen oppakken. De postdoc gaat de daadwerkelijke verbinding maken tussen onderzoekers, docenten en studenten. De postdoc ontwikkelt tevens projectleiderschapsvaardigheden door het volgen van een training en door lopende projecten binnen het MBBS onderzoek te benutten om samenwerking met (inter)nationale kennisinstellingen en bedrijven uit te bouwen. De postdoc zal begeleid en ondersteund worden in de uitvoering van haar activiteiten door lector en opleidingscoördinator (olc) (onder andere on the job en formele planningsafspraken), Centre of Expertise Biobased Economy (CoE BBE) alsmede het HZ kernteam CoE BBE (uitbouwen netwerk). Het personeelsbeleid en functiereeks onderwijs en onderzoek van de HZ voorzien in de ontwikkelingsmogelijkheid van de postdoc.
Proteins are nature-derived molecules that have found wide applications in biotechnology, pharmaceuticals and biocatalysis. A major limitation for the use of proteins in such applications is their lack of stability. This is due to the disruption of the tertiary structure of a protein, which is responsible for the function of a protein. Earlier studies have shown that three cysteine residues, which are strategically incorporated in the sequence, can be crosslinked with a tris-electrophile. This so-called in situ cyclization of proteins (INCYPRO) results in the rigidification of the protein structure and ultimately higher stability of the protein. For some proteins, it would be beneficial to use another amino acid residue for modification as cysteine residues can be important for the function of a protein, e.g. as disulfide bridges or as active sites residues. In this project, we will develop crosslinkers that are selective for methionine residues. Although these amino acids contribute to the function of proteins in biological systems, they are less important for the molecular function of proteins, thus making them suitable for crosslinking of proteins. Our plan is to first develop a set of trisfunctionalized crosslinkers that selectively react with the thioether functional group of methionine. Next, we will investigate the crosslinking conditions on the model protein (KIX domain) as a proof of concept. In the final step, we would like to prove that the function of the protein is retained by crosslinking the transpeptidase enzyme sortase A.
