scholarly journals High-Resolution Mass Spectrometry-Based Approaches for the Detection and Quantification of Peptidase Activity in Plasma

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4071
Author(s):  
Elisa Maffioli ◽  
Zhenze Jiang ◽  
Simona Nonnis ◽  
Armando Negri ◽  
Valentina Romeo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Proteolytic Activity ◽  
High Resolution Mass Spectrometry ◽  
Degradation Products ◽  
Quantitative Information ◽  
Peptidase Activity ◽  
Vitro Assay ◽  
Unbiased Manner

Proteomic technologies have identified 234 peptidases in plasma but little quantitative information about the proteolytic activity has been uncovered. In this study, the substrate profile of plasma proteases was evaluated using two nano-LC-ESI-MS/MS methods. Multiplex substrate profiling by mass spectrometry (MSP-MS) quantifies plasma protease activity in vitro using a global and unbiased library of synthetic peptide reporter substrates, and shotgun peptidomics quantifies protein degradation products that have been generated in vivo by proteases. The two approaches gave complementary results since they both highlight key peptidase activities in plasma including amino- and carboxypeptidases with different substrate specificity profiles. These assays provide a significant advantage over traditional approaches, such as fluorogenic peptide reporter substrates, because they can detect active plasma proteases in a global and unbiased manner, in comparison to detecting select proteases using specific reporter substrates. We discovered that plasma proteins are cleaved by endoproteases and these peptide products are subsequently degraded by amino- and carboxypeptidases. The exopeptidases are more active and stable in plasma and therefore were found to be the most active proteases in the in vitro assay. The protocols presented here set the groundwork for studies to evaluate changes in plasma proteolytic activity in shock.

In vitro and in vivo metabolism of 3-quinuclidinyl benzilate by high-resolution mass spectrometry

2020 ◽  
Vol 190 ◽  
pp. 113519
Author(s):  
Martin Uher ◽  
Martin Mžik ◽  
Jana Žďárová Karasová ◽  
David Herman ◽  
Lenka Čechová ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
In Vivo Metabolism ◽  
High Resolution Mass ◽  
Resolution Mass ◽  
Quinuclidinyl Benzilate

Identification of metabolites of peptide-derived drugs using an isotope-labeled reporter ion screening strategy

2020 ◽  
Vol 58 (5) ◽  
pp. 690-700 ◽  
Author(s):  
Andreas Thomas ◽  
Mario Thevis
Keyword(s):  
Stable Isotope ◽  
High Resolution Mass Spectrometry ◽  
Degradation Products ◽  
Screening Strategy ◽  
Biologically Active ◽  
Recombinant Human Insulin ◽  
Metabolic Processes ◽  
Metabolic Products

AbstractBackgroundPeptide-derived drugs represent an emerging class of prohibited substances in professional sports and, thus, in modern doping controls. After parental administration (e.g. subcutaneous, intravenous), these drugs undergo various metabolic processes, which degrade them to biologically active or inactive peptides. Knowledge about these metabolic processes and the hereby produced metabolites plays a key role in successful doping controls due to the effective design of analytical assays under consideration of optimal analytical targets. Unfortunately, the complexity of biological matrix (e.g. blood or urine) complicates the immediate identification of relevant metabolites due to the enormous excess of naturally occurring peptides and their degradation products.MethodsIn this study, a strategy employing in-vitro metabolism of stable isotope-labeled peptides producing characteristic reporter ions derived from labeled immonium ions is shown. The in-vitro experiments were performed with human skin tissue microsomes (S9), and model drugs representing prohibited peptide hormones were synacthen, insulin, and corticorelin (respectively, their stable isotope-labeled analogs). After generic sample preparation, the metabolites were identified by means of liquid chromatography (LC) coupled to high-resolution mass spectrometry (MS) in an untargeted approach.Results and conclusionsFor all three model peptides, several metabolic products were readily identified. While insulin and corticorelin were found to be comparably stable, synacthen was fully degraded, yielding a plethora of metabolic products. A proof of concept concerning the transferability of the obtained data was accomplished by analyzing plasma samples collected post-administration of recombinant human insulin, corroborating the presence of a skin protease-indicative insulin metabolite in vivo.

scholarly journals Implication of Opioid Receptors in the Antihypertensive Effect of a Novel Chicken Foot-Derived Peptide

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 992
Author(s):  
Anna Mas-Capdevila ◽  
Lisard Iglesias-Carres ◽  
Anna Arola-Arnal ◽  
Gerard Aragonès ◽  
Begoña Muguerza ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Opioid Receptors ◽  
High Performance ◽  
Antihypertensive Effect ◽  
High Resolution Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

The peptide AVFQHNCQE demonstrated to produce nitric oxide-mediated antihypertensive effect. This study investigates the bioavailability and the opioid-like activity of this peptide after its oral administration. For this purpose, in silico and in vitro approaches were used to study the peptide susceptibility to GI digestion. In addition, AVFQHNCQE absorption was studied both in vitro by using Caco-2 cell monolayers and in vivo evaluating peptide presence in plasma from Wistar rats by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Both in vivo and in vitro experiments demonstrated that peptide AVFQHNCQE was not absorbed. Thus, the potential involvement of opioid receptors in the BP-lowering effect of AVFQHNCQE was studied in the presence of opioid receptors-antagonist Naloxone. No changes in blood pressure were recorded in rats administered Naloxone, demonstrating that AVFQHNCQE antihypertensive effect is mediated through its interaction with opioid receptors. AVFQHNCQE opioid-like activity would clarify the antihypertensive properties of AVFQHNCQE despite its lack of absorption.

scholarly journals Monitoring metabolism of synthetic cannabinoid 4F-MDMB-BINACA via high-resolution mass spectrometry assessed in cultured hepatoma cell line, fungus, liver microsomes and confirmed using urine samples

2020 ◽  
Author(s):  
Huey Sze Leong ◽  
Shimpei Watanabe ◽  
Unnikrishnan Kuzhiumparambil ◽  
Ching Yee Fong ◽  
Hooi Yan Moy ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
High Resolution Mass Spectrometry ◽  
Liver Microsomes ◽  
Ester Hydrolysis ◽  
Butanoic Acid ◽  
C Elegans ◽  
Resolution Mass

Abstract Purpose A tert-leucinate derivative synthetic cannabinoid, methyl (2S)-2-([1-(4-fluorobutyl)-1H-indazole-3-carbonyl]amino)-3,3-dimethylbutanoate (4F-MDMB-BINACA, 4F-MDMB-BUTINACA or 4F-ADB) is known to adversely impact health. This study aimed to evaluate the suitability of three different modes of monitoring metabolism: HepG2 liver cells, fungus Cunninghamella elegans (C. elegans) and pooled human liver microsomes (HLM) for comparison with human in-vivo metabolism in identifying suitable urinary marker(s) for 4F-MDMB-BINACA intake. Methods Tentative structure elucidation of in-vitro metabolites was performed on HepG2, C. elegans and HLM using liquid chromatography–tandem mass spectrometry and high-resolution mass spectrometry analysis. In-vivo metabolites obtained from twenty authentic human urine samples were analysed using liquid chromatography–Orbitrap mass spectrometry. Results Incubation with HepG2, C. elegans and HLM yielded nine, twenty-three and seventeen metabolites of 4F-MDMB-BINACA, respectively, formed via ester hydrolysis, hydroxylation, carboxylation, dehydrogenation, oxidative defluorination, carbonylation or reaction combinations. Phase II metabolites of glucosidation and sulfation were also exclusively identified using C. elegans model. Eight in-vivo metabolites tentatively identified were mainly products of ester hydrolysis with or without additional dehydrogenation, N-dealkylation, monohydroxylation and oxidative defluorination with further oxidation to butanoic acid. Metabolites with intact terminal methyl ester moiety, i.e., oxidative defluorination with further oxidation to butanoic acid, were also tentatively identified. Conclusions The in-vitro models presented proved useful in the exhaustive metabolism studies. Despite limitations, HepG2 identified the major 4F-MDMB-BINACA ester hydrolysis metabolite, and C. elegans demonstrated the capacity to produce a wide variety of metabolites. Both C. elegans and HLM produced all the in-vivo metabolites. Ester hydrolysis and ester hydrolysis plus dehydrogenation 4F-MDMB-BINACA metabolites were recommended as urinary markers for 4F-MDMB-BINACA intake.

scholarly journals Studies on the in vitro and in vivo metabolism of the synthetic opioids U-51754, U-47931E, and methoxyacetylfentanyl using hyphenated high-resolution mass spectrometry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Frederike Nordmeier ◽  
Lilian H. J. Richter ◽  
Peter H. Schmidt ◽  
Nadine Schaefer ◽  
Markus R. Meyer
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Liver Microsomes ◽  
Rat Urine ◽  
Synthetic Opioids ◽  
High Resolution Mass ◽  
Resolution Mass

Abstract New Synthetic Opioids (NSOs) are one class of New Psychoactive Substances (NPS) enjoying increasing popularity in Europe. Data on their toxicological or metabolic properties have not yet been published for most of them. In this context, the metabolic fate of three NSOs, namely, trans-3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methyl-benzenacetamide (U-51754), trans-4-bromo-N-[2-(dimethylamino)cyclohexyl]-N-methyl-benzamide (U-47931E), and 2-methoxy-N-phenyl-N-[1-(2-phenylethyl)piperidin-4-yl] acetamide (methoxyacetylfentanyl), was elucidated by liquid chromatography high-resolution mass spectrometry after pooled human S9 fraction (phS9) incubations and in rat urine after oral administration. The following major reactions were observed: demethylation of the amine moiety for U-51754 and U-47931E, N-hydroxylation of the hexyl ring, and combinations thereof. N-dealkylation, O-demethylation, and hydroxylation at the alkyl part for methoxyacetylfentanyl. Except for U-47931E, parent compounds could only be found in trace amounts in rat urine. Therefore, urinary markers should preferably be metabolites, namely, the N-demethyl-hydroxy and the hydroxy metabolite for U-51754, the N-demethylated metabolite for U-47931E, and the N-dealkylated metabolite as well as the O-demethylated one for methoxyacetylfentanyl. In general, metabolite formation was comparable in vitro and in vivo, but fewer metabolites, particularly those after multiple reaction steps and phase II conjugates, were found in phS9. These results were consistent with those of comparable compounds obtained from human liver microsomes, human hepatocytes, and/or human case studies.

scholarly journals Protein Glycation in Diabetes as Determined by Mass Spectrometry

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Annunziata Lapolla ◽  
Laura Molin ◽  
Pietro Traldi
Keyword(s):  
Mass Spectrometry ◽  
Degradation Products ◽  
Glycated Haemoglobin ◽  
Maldi Mass Spectrometry ◽  
Enzymatic Digestion ◽  
Protein Glycation ◽  
Chronic Complications ◽  
Glycation End Products

Diabetes is a common endocrine disorder characterized by hyperglycemia leading to nonenzymatic glycation of proteins, responsible for chronic complications. The development of mass spectrometric techniques able to give highly specific and reliable results in proteome field is of wide interest for physicians, giving them new tools to monitor the disease progression and the possible complications related to diabetes, as well as the effectiveness of therapeutic treatments. This paper reports and discusses some of the data pertaining protein glycation in diabetic subjects obtained by matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS). The preliminary studies carried out byin vitroprotein glycation experiments show clear differences in molecular weight of glycated and unglycated proteins. Then, the attention was focused on plasma proteins human serum albumin (HSA) and immunoglobulin G (IgG). Enzymatic degradation products ofin vitroglycated HSA were studied in order to simulate thein vivoenzymatic digestion of glycated species by the immunological system leading to the highly reactive advanced glycation end-products (AGEs) peptides. Further studies led to the evaluation of glycated Apo A-I and glycated haemoglobin levels. A different MALDI approach was employed for the identification of markers of disease in urine samples of healthy, diabetic, nephropathic, and diabetic-nephropathic subjects.

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