1
|
Additive efficacy of a bispecific anti-TNF/IL-6 nanobody compound in translational models of rheumatoid arthritis. Sci Transl Med 2023; 15:eabq4419. [PMID: 36724239 DOI: 10.1126/scitranslmed.abq4419] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Rheumatoid arthritis (RA) is one of the most common autoimmune diseases affecting primarily the joints. Despite successful therapies including antibodies against tumor necrosis factor (TNF) and interleukin-6 (IL-6) receptor, only 20 to 30% of patients experience remission. We studied whether inhibiting both TNF and IL-6 would result in improved efficacy. Using backtranslation from single-cell RNA sequencing (scRNA-seq) data from individuals with RA, we hypothesized that TNF and IL-6 act synergistically on fibroblast-like synoviocytes (FLS) and T cells. Coculture of FLS from individuals with RA and T cells supported this hypothesis, revealing effects on both disease-driving pathways and biomarkers. Combining anti-TNF and anti-IL-6 antibodies in collagen-induced arthritis (CIA) mouse models resulted in sustained long-term remission, improved histology, and effects on bone remodeling pathways. These promising data initiated the development of an anti-TNF/IL-6 bispecific nanobody compound 1, with similar potencies against TNF and IL-6. We observed additive efficacy of compound 1 in a FLS/T cell coculture affecting arthritis and T helper 17 (TH17) pathways. This nanobody compound transcript signature inversely overlapped with described RA endotypes, indicating a potential efficacy in a broader patient population. In summary, we showed superiority of a bispecific anti-TNF/IL-6 nanobody compound or combination treatment over monospecific treatments in both in vitro and in vivo models. We anticipate improved efficacy in upcoming clinical studies.
Collapse
|
2
|
An orally available small molecule that targets soluble TNF to deliver anti-TNF biologic-like efficacy in rheumatoid arthritis. Front Pharmacol 2022; 13:1037983. [PMID: 36467083 PMCID: PMC9709720 DOI: 10.3389/fphar.2022.1037983] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/21/2022] [Indexed: 07/30/2023] Open
Abstract
Tumor necrosis factor (TNF) is a pleiotropic cytokine belonging to a family of trimeric proteins with both proinflammatory and immunoregulatory functions. TNF is a key mediator in autoimmune diseases and during the last couple of decades several biologic drugs have delivered new therapeutic options for patients suffering from chronic autoimmune diseases such as rheumatoid arthritis and chronic inflammatory bowel disease. Attempts to design small molecule therapies directed to this cytokine have not led to approved products yet. Here we report the discovery and development of a potent small molecule inhibitor of TNF that was recently moved into phase 1 clinical trials. The molecule, SAR441566, stabilizes an asymmetrical form of the soluble TNF trimer, compromises downstream signaling and inhibits the functions of TNF in vitro and in vivo. With SAR441566 being studied in healthy volunteers we hope to deliver a more convenient orally bioavailable and effective treatment option for patients suffering with chronic autoimmune diseases compared to established biologic drugs targeting TNF.
Collapse
|
3
|
EP08.01-027 Durvalumab (D) ± Tremelimumab (T) + Chemotherapy (CT) in 1L Metastatic NSCLC: Outcomes by Tumour PD-L1 Expression in POSEIDON. J Thorac Oncol 2022. [DOI: 10.1016/j.jtho.2022.07.599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
4
|
Enhanced access to EGFR molecular testing in NSCLC using a cell-free DNA tube for liquid biopsy. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz257.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
5
|
Mechanistic investigations of the liver toxicity of the free fatty acid receptor 1 agonist fasiglifam (TAK875) and its primary metabolites. J Biochem Mol Toxicol 2019; 33:e22345. [DOI: 10.1002/jbt.22345] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 01/23/2019] [Accepted: 04/04/2019] [Indexed: 12/21/2022]
|
6
|
Identification and characterisation of carnostatine (SAN9812), a potent and selective carnosinase (CN1) inhibitor with in vivo activity. Amino Acids 2018; 51:7-16. [DOI: 10.1007/s00726-018-2601-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/05/2018] [Indexed: 12/30/2022]
|
7
|
Home-centered Health-enabling Technologies and Regional Health Information Systems. Methods Inf Med 2018; 53:160-6. [DOI: 10.3414/me13-02-0008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 11/06/2013] [Indexed: 11/09/2022]
Abstract
SummaryIntroduction: This article is part of the Focus Theme of Methods of Information in Medicine on “Using Data from Ambient Assisted Living and Smart Homes in Electronic Health Records”.Objectives: In this paper, we present a prototype of a Home-Centered Health- Enabling Technology (HET-HC), which is able to capture, store, merge and process data from various sensor systems at people’s home. In addition, we present an architecture designed to integrate HET-HC into an exem -plary regional Health Information System (rHIS).Methods: rHIS are traditionally document-based to fit to the needs in a clinical context. However, HET-HC are producing continuous data streams for which documents might be an inappropriate representation. Therefore, the HET-HC could register placeholder-documents at rHIS. These placeholder-documents are assembled upon user-authenticated request by the HET-HC and are always up-to-date. Moreover, it is not trivial to find a clinical coding system for continuous sensor data and to make the data machine-readable in order to enhance the interoperability of such systems. Therefore, we propose the use of SNOCAP-HET, which is a nomenclature to describe the context of sensor-based measurements in health-enabling technologies.Results: We present an architectural approach to integrate HET-HC into rHIS. Our solution is the centralized registration of placeholder-documents with rHIS and the decentralized data storage at people’s home.Conclusions: We concluded that the pre -sented architecture of integrating HET-HC into rHIS might fit well to the traditional approach of document-based data storage. Data security and privacy issues are also duly considered.
Collapse
|
8
|
Sulfamide as Zinc Binding Motif in Small Molecule Inhibitors of Activated Thrombin Activatable Fibrinolysis Inhibitor (TAFIa). J Med Chem 2016; 59:9567-9573. [PMID: 27749053 DOI: 10.1021/acs.jmedchem.6b01276] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previously disclosed TAFIa inhibitors having a urea zinc-binding motif were used as the starting point for the development of a novel class of highly potent inhibitors having a sulfamide zinc-binding motif. High-resolution X-ray cocrystal structures were used to optimize the structures and reveal a highly unusual sulfamide configuration. A selected sulfamide was profiled in vitro and in vivo and displayed a promising ADMET profile.
Collapse
|
9
|
In vivo visualization of osteoarthritic hypertrophic lesions. Chem Sci 2015; 6:6256-6261. [PMID: 30090244 PMCID: PMC6054140 DOI: 10.1039/c5sc01301a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/12/2015] [Indexed: 11/25/2022] Open
Abstract
Osteoarthritis (OA) is one of the most common diseases in the aging population. While disease progress in humans is monitored indirectly by X-ray or MRI, small animal OA lesions detection always requires surgical intervention and histology. Here we introduce bimodal MR/NIR probes based on cartilage-targeting 1,4,7,10-tetraazacyclododecane 1,4,7,10-tetraacetic acid amide (DOTAM) that are directly administered to the joint cavity. We demonstrate applications in healthy and diseased rat joints by MRI in vivo. The same joints are inspected post-mortem by fluorescence microscopy, showing not only the precise location of the reagents but also revealing details such as focal cartilage damage and chondrophyte or osteophyte formation. This allows for determining the distinct pathological state of the disease and the regeneration capability of the animal model and will help to correctly assess the effect of potential disease modifying OA drugs (DMOADs) in the future.
Collapse
|
10
|
Abstract
The discovery of Streptomyces-produced streptomycin founded the age of tuberculosis therapy. Despite the subsequent development of a curative regimen for this disease, tuberculosis remains a worldwide problem, and the emergence of multidrug-resistant Mycobacterium tuberculosis has prioritized the need for new drugs. Here we show that new optimized derivatives from Streptomyces-derived griselimycin are highly active against M. tuberculosis, both in vitro and in vivo, by inhibiting the DNA polymerase sliding clamp DnaN. We discovered that resistance to griselimycins, occurring at very low frequency, is associated with amplification of a chromosomal segment containing dnaN, as well as the ori site. Our results demonstrate that griselimycins have high translational potential for tuberculosis treatment, validate DnaN as an antimicrobial target, and capture the process of antibiotic pressure-induced gene amplification.
Collapse
|
11
|
Mass Spectrometric Analysis of Noncovalent Complexes Between Synthetic Peptides from Human Ribosomal Protein L7 and Protein G. J LIQ CHROMATOGR R T 2015. [DOI: 10.1080/10826076.2014.922475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
12
|
Characterization of Non-Covalent Complexes of Synthetic Peptides of RNA Polymerase Subunit σ70 From Chlamydia trachomatiswith Protein G by nanoESI-MS. J LIQ CHROMATOGR R T 2015. [DOI: 10.1080/10826076.2014.968661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
13
|
Novel Small Molecule Inhibitors of Activated Thrombin Activatable Fibrinolysis Inhibitor (TAFIa) from Natural Product Anabaenopeptin. J Med Chem 2015; 58:4839-44. [PMID: 25990761 DOI: 10.1021/jm501840b] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Anabaenopeptins isolated from cyanobacteria were identified as inhibitors of carboxypeptidase TAFIa. Cocrystal structures of these macrocyclic natural product inhibitors in a modified porcine carboxypeptidase B revealed their binding mode and provided the basis for the rational design of small molecule inhibitors with a previously unknown central urea motif. Optimization based on these design concepts allowed for a rapid evaluation of the SAR and delivered potent small molecule inhibitors of TAFIa with a promising overall profile.
Collapse
|
14
|
End-organ protection in hypertension by the novel and selective Rho-kinase inhibitor, SAR407899. World J Cardiol 2015; 7:31-42. [PMID: 25632317 PMCID: PMC4306204 DOI: 10.4330/wjc.v7.i1.31] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 12/01/2014] [Accepted: 12/31/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To compare the therapeutic efficacy of SAR407899 with the current standard treatment for hypertension [an angiotensin converting enzyme (ACE)-inhibitor and a calcium channel blocker] and compare the frequency and severity of the hypertension-related end-organ damage.
METHODS: Long-term pharmacological characte-rization of SAR407899 has been performed in two animal models of hypertension, of which one is sensitive to ACE-inhibition (LNAME) and the other is insensitive [deoxycorticosterone acetate (DOCA)]. SAR407899 efficiently lowered high blood pressure and significantly reduced late-stage end organ damage as indicated by improved heart, kidney and endothelial function and reduced heart and kidney fibrosis in both models of chronic hypertension.
RESULTS: Long term treatment with SAR407899 has been well tolerated and dose-dependently reduced elevated blood pressure in both models with no signs of tachyphylaxia. Blood pressure lowering effects and protective effects on hypertension related end organ damage of SAR407899 were superior to ramipril and amlodipine in the DOCA rat. Typical end-organ damage was significantly reduced in the SAR407899-treated animals. Chronic administration of SAR407899 significantly reduced albuminuria in both models. The beneficial effect of SAR407899 was associated with a reduction in leukocyte/macrophage tissue infiltration. The overall protective effect of SAR407899 was superior or comparable to that of ACE-inhibition or calcium channel blockade. Chronic application of SAR407899 protects against hypertension and hypertension-induced end organ damage, regardless of the pathophysiological mechanism of hypertension.
CONCLUSION: Rho-kinases-inhibition by the SAR407899 represents a new therapeutic option for the treatment of hypertension and its complications.
Collapse
|
15
|
Small Macrocycles As Highly Active Integrin α2β1 Antagonists. ACS Med Chem Lett 2014; 5:193-8. [PMID: 24900800 DOI: 10.1021/ml4004556] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 01/08/2014] [Indexed: 01/17/2023] Open
Abstract
Starting from clinical candidates Firategrast, Valategrast, and AJM-300, a series of novel macrocyclic platelet collagen receptor α2β1 antagonists were developed. The amino acid derived low molecular weight 14-18-membered macrocycles turned out to be highly active toward integrin α2β1 with IC50s in the low nanomolar range. The conformation of the macrocycles was found to be highly important for the activity, and an X-ray crystal structure was obtained to clarify this. Subsequent docking into the metal-ion-dependent adhesion site (MIDAS) of a β1 unit revealed a binding model indicating key binding features. Macrocycle 38 was selected for further in vitro and in vivo profiling.
Collapse
|
16
|
Measurement of accelerometry-based gait parameters in people with and without dementia in the field: a technical feasibility study. Methods Inf Med 2013; 52:319-25. [PMID: 23807731 DOI: 10.3414/me12-02-0009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 04/09/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND Gait analyses are an important tool to diagnose diseases or to measure the rehabilitation process of patients. In this context, sensor-based systems, and especially accelerometers, gain in importance. They are able to improve objectiveness of gait analyses. In clinical settings, there is usually a supervisor who gives instructions to the patients, but this can have an influence on patients' gait. It is expected that this effect will be smaller in field studies. OBJECTIVE Aim of this study was to capture and evaluate gait parameters measured by a single waist-mounted accelerometer during everyday life of subjects. METHODS Due to missing ground-truth in unsupervised conditions, another external criterion had to be chosen. Subjects of two different groups were considered: patients with dementia (DEM) and active older people (ACT). These groups were chosen, because of the expected difference in gait. The idea was to quantify the expected difference of accelerometric-based gait parameters. Gait parameters were e.g. velocity, step frequency, compensation movements, and variance of the accelerometric signal. RESULTS Ten subjects were measured in each group. The number of walking episodes captured was 1,187 (DEM) vs. 1,809 (ACT). The compensation and variance parameters showed an AUC value (Area Under the Curve) between 0.88 and 0.92. In contrast, velocity and step frequency performed poorly (AUC values of 0.51 and 0.55). It was possible to classify both groups using these parameters with an accuracy of 89.2%. CONCLUSION The results showed a much higher amount of walking episodes in field studies compared to supervised clinical trials. The classification showed a high accuracy in distinguishing between both groups.
Collapse
|
17
|
Discovery and pharmacological characterization of SAR707 as novel and selective small molecule inhibitor of stearoyl-CoA desaturase (SCD1). Eur J Pharmacol 2013; 707:140-6. [DOI: 10.1016/j.ejphar.2013.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 03/08/2013] [Accepted: 03/13/2013] [Indexed: 01/22/2023]
|
18
|
Identification of High-Affinity P2Y12 Antagonists Based on a Phenylpyrazole Glutamic Acid Piperazine Backbone. J Med Chem 2012; 55:8615-29. [DOI: 10.1021/jm300771j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
19
|
|
20
|
Abstract
Recent advances in basic and clinical research have identified Rho kinase as an important target potentially implicated in a variety of cardiovascular diseases. Rho kinase is a downstream mediator of RhoA that leads to stress fiber formation, membrane ruffling, smooth muscle contraction, and cell motility. Increased Rho-kinase activity is associated with vasoconstriction and elevated blood pressure. We identified a novel inhibitor of Rho kinase (SAR407899) and characterized its effects in biochemical, cellular, tissue-based, and in vivo assays. SAR407899 is an ATP-competitive Rho-kinase inhibitor, equipotent against human and rat-derived Rho-kinase 2 with inhibition constant values of 36 nM and 41 nM, respectively. It is highly selective in panel of 117 receptor and enzyme targets. SAR407899 is approximately 8-fold more active than fasudil. In vitro, SAR407899 demonstrated concentration-dependent inhibition of Rho-kinase-mediated phosphorylation of myosin phosphatase, thrombin-induced stress fiber formation, platelet-derived growth factor-induced proliferation, and monocyte chemotactic protein-1-stimulated chemotaxis. SAR407899 potently (mean IC(50) values: 122 to 280 nM) and species-independently relaxed precontracted isolated arteries of different species and different vascular beds. In vivo, over the dose range 3 to 30 mg/kg PO, SAR407899 lowered blood pressure in a variety of rodent models of arterial hypertension. The antihypertensive effect of SAR407899 was superior to that of fasudil and Y-27632. In conclusion, SAR407899 is a novel and potent selective Rho-kinase inhibitor with promising antihypertensive activity.
Collapse
|
21
|
Differential epitope identification of antibodies against intracellular domains of alzheimer's amyloid precursor protein using high resolution affinity-mass spectrometry. Subcell Biochem 2007; 43:339-354. [PMID: 17953402 DOI: 10.1007/978-1-4020-5943-8_16] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Several polypeptides comprising the carboxy-terminal domain of the 1-amyloid precursor protein (cAPP) were prepared by solid phase peptide synthesis, and employed as antigens for the determination of the epitopes recognised by anti-cAPP antibodies. Selective proteolytic epitope-excision and -extraction on the immobilised immune complexes, in combination with high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) were used as major methods for epitope identification. The epitope recognised by a polyclonal anti-cAPP antibody (36-BO) was identified as APP(727-737), a sequence close to the APP transmembrane region. In contrast, the epitope recognised by a monoclonal anti-cAPP antibody (Jonas-mAb) was identified at APP(740-747) to be located more remote from the transmembrane region. The two adjacent, yet distinct epitopes recognised by two different antibodies should provide efficient tools for (i), molecular diagnostic applications, and (ii), the study of intracellular processing pathways of APP relevant to Alzheimer's disease, utilising suitable mass spectrometric and molecular imaging approaches.
Collapse
|
22
|
Identification and structural characterisation of carboxy-terminal polypeptides and antibody epitopes of Alzheimer's amyloid precursor protein using high-resolution mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2005; 11:547-56. [PMID: 16322661 DOI: 10.1255/ejms.722] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Alzheimer's disease (AD) is the most common cause for human age-related dementia, characterised by formation of diffuse plaques in brain that are directly involved in AD pathogenesis. The major component of AD plaques is beta-amyloid, a 40 to 42 amino acid polypeptide derived from the amyloid precursor protein (APP) by proteolytic degradation involving the specific proteases, beta-and gamma-secretase acting at the N- and C- terminal cleavage site, respectively. In this study we have prepared polypeptides comprising the carboxy-terminal and transmembrane sequences of APP, by bacterial expression and chemical synthesis, as substrates for studying the C-terminal processing of APP and its interaction with the gamma-secretase complex. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was used as a major tool for structure analysis. Immunisation of transgenic mouse models of AD with Abeta42 has been recently shown to be effective to inhibit and disaggregate Abeta-fibrils, and to reduce AD-related neuropathology and memory impairments. However, the mechanism underlying these therapeutic effects has been as yet unclear. Using proteolytic epitope excision from immune complexes in combination with FT-ICR-MS, we identified the epitope recognised by the therapeutically active antibody as the N-terminal Abeta(4-10) sequence; this soluble, nontoxic epitope opens new lead structures for AD vaccine development. A monoclonal antibody (Jonas; JmAb) directed against the cytosolic APP domain was used in studies of APP biochemistry and metabolism. Here we report the identification of the epitope recognised by the JmAb, using the combination of epitope excision and peptide mapping by FT-ICR-MS. The epitope was determined to be located at the C-terminal APP(740-747) sequence; it was confirmed by ELISA binding assays and authentic synthetic peptides and will be an efficient tool in the development of new specific vaccines. These results demonstrate high-resolution FT-ICR-MS as a powerful method for characterising biochemical pathways and molecular recognition structures of APP.
Collapse
|
23
|
"Affinity-proteomics": direct protein identification from biological material using mass spectrometric epitope mapping. Anal Bioanal Chem 2004; 378:1102-11. [PMID: 12955276 DOI: 10.1007/s00216-003-2159-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2003] [Revised: 06/30/2003] [Accepted: 07/04/2003] [Indexed: 11/28/2022]
Abstract
We describe here a new approach for the identification of affinity-bound proteins by proteolytic generation and mass spectrometric analysis of their antibody bound epitope peptides (epitope excision). The cardiac muscle protein troponin T was chosen as a protein antigen because of its diagnostic importance in myocardial infarct, and its previously characterised epitope structure. Two monoclonal antibodies (IgG1-1B10 and IgG1-11.7) raised against intact human troponin T were found to be completely cross reactive with bovine heart troponin T. A combination of immuno-affinity isolation, partial proteolytic degradation (epitope excision), mass spectrometric peptide mapping, and database analysis was used for the direct identification of Tn T from bovine heart cell lysate. Selective binding of the protein was achieved by addition of bovine heart cell lysate to the Sepharose-immobilised monoclonal antibodies, followed by removal of supernatant material containing unbound protein. While still bound to the affinity matrix the protein was partially degraded thereby generating a set of affinity-bound, overlapping peptide fragments comprising the epitope. Following dissociation from the antibody the epitope peptides were analysed by matrix assisted laser desorption-ionisation (MALDI) and electrospray-ionisation (ESI) mass spectrometry. The peptide masses identified by mass spectrometry were used to perform an automated database search, combined with a search for a common "epitope motif". This procedure resulted in the unequivocal identification of the protein from biological material with only a minimum number of peptide masses, and requiring only limited mass-determination accuracy. The dramatic increase of selectivity for identification of the protein by combining the antigen-antibody specificity with the redundancy of peptide sequences renders this "affinity-proteomics" approach a powerful tool for mass spectrometric identification of proteins from biological material.
Collapse
|
24
|
Metabolic profiling of oxylipins upon sorbitol treatment in barley leaves. Biochem Soc Trans 2000; 28:861-2. [PMID: 11171234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
In barley leaves 13-lipoxygenases (LOXs) are induced by salicylate and jasmonate. Here, we analyse by metabolic profiling the accumulation of oxylipins upon sorbitol treatment. Although 13-LOX-derived products are formed and specifically directed into the reductase branch of the LOX pathway, accumulation is much later than in the cases of salicylate and jasmonate treatment. In addition, under these conditions only the accumulation of jasmonates as additional products of the LOX pathway has been found.
Collapse
|
25
|
Formation of lipoxygenase-pathway-derived aldehydes in barley leaves upon methyl jasmonate treatment. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 260:885-95. [PMID: 10103020 DOI: 10.1046/j.1432-1327.1999.00231.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In barley leaves, the application of jasmonates leads to dramatic alterations of gene expression. Among the up-regulated gene products lipoxygenases occur abundantly. Here, at least four of them were identified as 13-lipoxygenases exhibiting acidic pH optima between pH 5.0 and 6.5. (13S,9Z,11E,15Z)-13-hydroxy-9,11,15-octadecatrienoic acid was found to be the main endogenous lipoxygenase-derived polyenoic fatty acid derivative indicating 13-lipoxygenase activity in vivo. Moreover, upon methyl jasmonate treatment > 78% of the fatty acid hydroperoxides are metabolized by hydroperoxide lyase activity resulting in the endogenous occurrence of volatile aldehydes. (2E)-4-Hydroxy-2-hexenal, hexanal and (3Z)- plus (2E)-hexenal were identified as 2,4-dinitro-phenylhydrazones using HPLC and identification was confirmed by GC/MS analysis. This is the first proof that (2E)-4-hydroxy-2-hexenal is formed in plants under physiological conditions. Quantification of (2E)-4-hydroxy-2-hexenal, hexanal and hexenals upon methyl jasmonate treatment of barley leaf segments revealed that hexenals were the major aldehydes peaking at 24 h after methyl jasmonate treatment. Their endogenous content increased from 1.6 nmol.g-1 fresh weight to 45 nmol.g-1 fresh weight in methyl-jasmonate-treated leaf segments, whereas (2E)-4-hydroxy-2-hexenal, peaking at 48 h of methyl jasmonate treatment increased from 9 to 15 nmol.g-1 fresh weight. Similar to the hexenals, hexanal reached its maximal amount 24 h after methyl jasmonate treatment, but increased from 0.6 to 3.0 nmol.g-1 fresh weight. In addition to the classical leaf aldehydes, (2E)-4-hydroxy-2-hexenal was detected, thereby raising the question of whether it functions in the degradation of chloroplast membrane constituents, which takes place after methyl jasmonate treatment.
Collapse
|
26
|
Spectrophotometric assay for amidolytic activity of alkaline protease from Pseudomonas aeruginosa. Anal Chim Acta 1997. [DOI: 10.1016/s0003-2670(97)00024-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
27
|
Amphetamine and methamphetamine determination in urine by reversed-phase high-performance liquid chromatography with simultaneous sample clean-up and derivatization with 1,2-naphthoquinone 4-sulphonate on solid-phase cartridges. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 687:239-46. [PMID: 9001969 DOI: 10.1016/s0378-4347(96)00067-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A liquid-solid procedure is proposed for sample clean-up and derivatization of amphetamine and methamphetamine in urine samples. The reagent was 1,2-naphthoquinone 4-sulphonate, and a commercial C18 packing cartridge was used. The samples derivatized at room temperature were chromatographed on a 5-microns Hypersil ODS (250 x 4 mm I.D.) with an elution gradient of acetonitrile-water containing propylamine. Under these conditions, the amines were eluted with short retention times. The procedure was used to determine amphetamine, or methamphetamine with its metabolite amphetamine, in spiked urine samples. The detection limit (at a signal-to-noise ratio of 3) for amphetamine (0.1 microgram/ml) was similar to that obtained with liquid-liquid derivatization and to those obtained with immobilized reagents on a polymeric solid support. The detection limit for methamphetamine (0.4 microgram/ml) was higher than with the liquid-liquid procedure because of the lower reactivity on the cartridge. The precision and accuracy of the method were also studied.
Collapse
|
28
|
|
29
|
Mechanisms of improved physical performance of chronic hemodialysis patients after erythropoietin treatment. Am J Nephrol 1990; 10 Suppl 2:15-8; discussion 18-23. [PMID: 2124412 DOI: 10.1159/000168211] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Correction of the anemia that is common among chronic hemodialysis patients by treatment with human recombinant erythropoietin (rHuEPO), even if incomplete, improves physical performance of patients. Oxygen uptake and physical work capacity at maximal work loads and at the anaerobic threshold increase by approximately 20%. Analysis of underlying mechanisms by pulmonary function tests and ergospirometry demonstrate that improved oxygen transport in the blood and its concomitant changes of the anaerobic threshold and heart rate appear to be main causes of improvement. Parameters of respiratory mechanics and gas exchange remain essentially unaltered.
Collapse
|
30
|
|