1
|
Rasmussen M, Welinder C, Schwede F, Ekström P. The stereospecific interaction sites and target specificity of cGMP analogs in mouse cortex. Chem Biol Drug Des 2021; 99:206-221. [PMID: 34687134 DOI: 10.1111/cbdd.13976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/29/2021] [Accepted: 10/16/2021] [Indexed: 11/30/2022]
Abstract
cGMP interactors play a role in several pathologies and may be targets for cGMP analog-based drugs, but the success of targeting depends on the biochemical stereospecificity between the cGMP-analog and the interactor. The stereospecificity between general cGMP analogs-or such that are selectivity-modified to obtain, for example, inhibitory actions on a specific target, like the cGMP-dependent protein kinase-have previously been investigated. However, the importance of stereospecificity for cGMP-analog binding to interactors is not known. We, therefore, applied affinity chromatography on mouse cortex proteins utilizing analogs with cyclic phosphate (8-AET-cGMP, 2-AH-cGMP, 2'-AHC-cGMP) and selectivity-modified analogs with sulfur-containing cyclic phosphorothioates (Rp/Sp-8-AET-cGMPS, Rp/Sp-2'-AHC-cGMPS) immobilized to agaroses. The results illustrate the cGMP analogs' stereospecific binding for PKG, PKA regulatory subunits and PKA catalytic subunits, PDEs, and EPAC2 and the involvement of these in various KEGG pathways. For the seven agaroses, PKG, PKA regulatory subunits, and PKA catalytic subunits were more prone to be enriched by 2-AH-, 8-AET-, Rp-8-AET-, and Sp-8-AET-cGMP, whereas PDEs and EPAC2 were more likely to be enriched by 2-AH-, Rp-2'-AHC-, and Rp-8-AET-cGMP. Our findings help elucidate the stereospecific-binding sites essential for the interaction between individual cGMP analogs and cGMP-binding proteins, as well as the cGMP analogs' target specificity, which are two crucial parameters in drug design.
Collapse
Affiliation(s)
- Michel Rasmussen
- Faculty of Medicine, Department of Clinical Sciences Lund, Ophthalmology, Lund University, Lund, Sweden
| | - Charlotte Welinder
- Faculty of Medicine, Department of Clinical Sciences Lund, Oncology, Lund University, Lund, Sweden
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co. KG, Bremen, Germany
| | - Per Ekström
- Faculty of Medicine, Department of Clinical Sciences Lund, Ophthalmology, Lund University, Lund, Sweden
| |
Collapse
|
2
|
Rasmussen M, Welinder C, Schwede F, Ekström P. The cGMP system in normal and degenerating mouse neuroretina: New proteins with cGMP interaction potential identified by a proteomics approach. J Neurochem 2020; 157:2173-2186. [PMID: 33230839 PMCID: PMC8359485 DOI: 10.1111/jnc.15251] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/17/2022]
Abstract
The hereditary disease Retinitis pigmentosa results in severe vision loss due to photoreceptor degeneration by unclear mechanisms. In several disease models, the second messenger cGMP accumulates in the degenerating photoreceptors, where it may over‐activate specific cGMP‐interacting proteins, like cGMP‐dependent protein kinase. Moreover, interventions that counteract the activity of these proteins lead to reduced photoreceptor cell death. Yet there is little or no information whether other than such regular cGMP‐interactors are present in the retina, which we, therefore, investigated in wild‐type and retinal degeneration (rd1, rd10, and rd2) mouse models. An affinity chromatography based proteomics approach that utilized immobilized cGMP analogs was applied to enrich and select for regular and potentially new cGMP‐interacting proteins as identified by mass spectrometry. This approach revealed 12 regular and 10 potentially new retinal cGMP‐interacting proteins (e.g., EPAC2 and CaMKIIα). Several of the latter were found to be expressed in the photoreceptors and to have proximity to cGMP and may thus be of interest when defining prospective therapeutic targets or biomarkers for retinal degeneration.
Collapse
Affiliation(s)
- Michel Rasmussen
- Faculty of Medicine, Department of Clinical Sciences Lund, Lund University, Ophthalmology, Lund, Sweden
| | - Charlotte Welinder
- Faculty of Medicine, Department of Clinical Sciences Lund, Oncology, Lund University, Lund, Sweden
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co. KG, Bremen, Germany
| | - Per Ekström
- Faculty of Medicine, Department of Clinical Sciences Lund, Lund University, Ophthalmology, Lund, Sweden
| |
Collapse
|
3
|
Akashi S, Ahmed KA, Sawa T, Ono K, Tsutsuki H, Burgoyne JR, Ida T, Horio E, Prysyazhna O, Oike Y, Rahaman MM, Eaton P, Fujii S, Akaike T. Persistent Activation of cGMP-Dependent Protein Kinase by a Nitrated Cyclic Nucleotide via Site Specific Protein S-Guanylation. Biochemistry 2016; 55:751-61. [PMID: 26784639 DOI: 10.1021/acs.biochem.5b00774] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
8-Nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP) is a nitrated derivative of guanosine 3',5'-cyclic monophosphate (cGMP) formed endogenously under conditions associated with production of both reactive oxygen species and nitric oxide. It acts as an electrophilic second messenger in the regulation of cellular signaling by inducing a post-translational modification of redox-sensitive protein thiols via covalent adduction of cGMP moieties to protein thiols (protein S-guanylation). Here, we demonstrate that 8-nitro-cGMP potentially S-guanylates thiol groups of cGMP-dependent protein kinase (PKG), the enzyme that serves as one of the major receptor proteins for intracellular cGMP and controls a variety of cellular responses. S-Guanylation of PKG was found to occur in a site specific manner; Cys42 and Cys195 were the susceptible residues among 11 Cys residues. Importantly, S-guanylation at Cys195, which is located in the high-affinity cGMP binding domain of PKG, causes persistent enzyme activation as determined by in vitro kinase assay as well as by an organ bath assay. In vivo, S-guanylation of PKG was demonstrated to occur in mice without any specific treatment and was significantly enhanced by lipopolysaccharide administration. These findings warrant further investigation in terms of the physiological and pathophysiological roles of S-guanylation-dependent persistent PKG activation.
Collapse
Affiliation(s)
- Soichiro Akashi
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Khandaker Ahtesham Ahmed
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Tomohiro Sawa
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency , Kawaguchi, Saitama 332-0012, Japan
| | - Katsuhiko Ono
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Hiroyasu Tsutsuki
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan
| | - Joseph R Burgoyne
- Department of Cardiology, Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital , London SE1 7EH, U.K
| | - Tomoaki Ida
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Eiji Horio
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University , Honjo 1-1-1, Kumamoto 860-8556, Japan
| | - Oleksandra Prysyazhna
- Department of Cardiology, Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital , London SE1 7EH, U.K
| | - Yuichi Oike
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University , Honjo 1-1-1, Kumamoto 860-8556, Japan
| | - Mizanur Md Rahaman
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Philip Eaton
- Department of Cardiology, Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital , London SE1 7EH, U.K
| | - Shigemoto Fujii
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Takaaki Akaike
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine , 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| |
Collapse
|
4
|
Ji HL, Nie HG, Chang Y, Lian Q, Liu SL. CPT-cGMP Is A New Ligand of Epithelial Sodium Channels. Int J Biol Sci 2016; 12:359-66. [PMID: 27019621 PMCID: PMC4807156 DOI: 10.7150/ijbs.13764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/11/2015] [Indexed: 12/28/2022] Open
Abstract
Epithelial sodium channels (ENaC) are localized at the apical membrane of the epithelium, and are responsible for salt and fluid reabsorption. Renal ENaC takes up salt, thereby controlling salt content in serum. Loss-of-function ENaC mutations lead to low blood pressure due to salt-wasting, while gain-of-function mutations cause impaired sodium excretion and subsequent hypertension as well as hypokalemia. ENaC activity is regulated by intracellular and extracellular signals, including hormones, neurotransmitters, protein kinases, and small compounds. Cyclic nucleotides are broadly involved in stimulating protein kinase A and protein kinase G signaling pathways, and, surprisingly, also appear to have a role in regulating ENaC. Increasing evidence suggests that the cGMP analog, CPT-cGMP, activates αβγ-ENaC activity reversibly through an extracellular pathway in a dose-dependent manner. Furthermore, the parachlorophenylthio moiety and ribose 2'-hydroxy group of CPT-cGMP are essential for facilitating the opening of ENaC channels by this compound. Serving as an extracellular ligand, CPT-cGMP eliminates sodium self-inhibition, which is a novel mechanism for stimulating salt reabsorption in parallel to the traditional NO/cGMP/PKG signal pathway. In conclusion, ENaC may be a druggable target for CPT-cGMP, leading to treatments for kidney malfunctions in salt reabsorption.
Collapse
Affiliation(s)
- Hong-Long Ji
- 1. Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
| | - Hong-Guang Nie
- 2. Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang 110001, China
| | - Yongchang Chang
- 3. Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, 85013, USA
| | - Qizhou Lian
- 4. Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Shan-Lu Liu
- 5. Department of Molecular Microbiology and Immunology, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| |
Collapse
|
5
|
Huang SH, Wang X, Jong A. The evolving role of infectomics in drug discovery. Expert Opin Drug Discov 2013; 2:961-75. [PMID: 23484816 DOI: 10.1517/17460441.2.7.961] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Signatures of infectomes, which are encoded by both host and microbial genomes, and mirror the interplay between pathogens and their hosts, provide invaluable knowledge in the search for novel antimicrobial drugs. Infectomics is the study of infectomes by using systems biology and high-throughput omic approaches. There are three types of infectomic approaches that can be used for drug discovery: ecological infectomics, immunoinfectomics and chemical infectomics. Ecological infectomics, which is the ecological study of infectomes, explores symbiotic solutions to microbial infections. Research on drug discovery using infectomic signatures and immunomic approaches falls within the field of immunoinfectomics. Advances in chemical infectomics will lead to the development of a new generation of chemical drugs for therapeutics for microbial infections.
Collapse
Affiliation(s)
- Sheng-He Huang
- University of Southern California, Division of Infectious Diseases, Childrens Hospital Los Angeles, Department of Pediatrics, School of Medicine, 4650 Sunset Blvd., Mailstop #51, Los Angeles, CA 90027, USA +1 323 669 4160 ; +1 323 660 2661 ;
| | | | | |
Collapse
|
6
|
Donaldson L, Meier S. An affinity pull-down approach to identify the plant cyclic nucleotide interactome. Methods Mol Biol 2013; 1016:155-73. [PMID: 23681578 DOI: 10.1007/978-1-62703-441-8_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cyclic nucleotides (CNs) are intracellular second messengers that play an important role in mediating physiological responses to environmental and developmental signals, in species ranging from bacteria to humans. In response to these signals, CNs are synthesized by nucleotidyl cyclases and then act by binding to and altering the activity of downstream target proteins known as cyclic nucleotide-binding proteins (CNBPs). A number of CNBPs have been identified across kingdoms including transcription factors, protein kinases, phosphodiesterases, and channels, all of which harbor conserved CN-binding domains. In plants however, few CNBPs have been identified as homology searches fail to return plant sequences with significant matches to known CNBPs. Recently, affinity pull-down techniques have been successfully used to identify CNBPs in animals and have provided new insights into CN signaling. The application of these techniques to plants has not yet been extensively explored and offers an alternative approach toward the unbiased discovery of novel CNBP candidates in plants. Here, an affinity pull-down technique for the identification of the plant CN interactome is presented. In summary, the method involves an extraction of plant proteins which is incubated with a CN-bait, followed by a series of increasingly stringent elutions that eliminates proteins in a sequential manner according to their affinity to the bait. The eluted and bait-bound proteins are separated by one-dimensional gel electrophoresis, excised, and digested with trypsin after which the resultant peptides are identified by mass spectrometry-techniques that are commonplace in proteomics experiments. The discovery of plant CNBPs promises to provide valuable insight into the mechanism of CN signal transduction in plants.
Collapse
Affiliation(s)
- Lara Donaldson
- Division of Chemical and Life Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | | |
Collapse
|
7
|
Ramchandran R, Pilipenko E, Bach L, Raghavan A, Reddy SP, Raj JU. Hypoxic regulation of pulmonary vascular smooth muscle cyclic guanosine monophosphate-dependent kinase by the ubiquitin conjugating system. Am J Respir Cell Mol Biol 2011; 46:323-30. [PMID: 21997485 DOI: 10.1165/rcmb.2011-0165oc] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We previously reported that hypoxia attenuates nitric oxide-cyclic guanosine monophosphate (NO-cGMP)-mediated fetal pulmonary vessel relaxation by inhibiting cGMP-dependent protein kinase 1 (PKG1) activity, but not all the mechanisms by which acute hypoxia inhibits PKG1 activity have been delineated. Here we demonstrate for the first time, to the best of our knowledge, that acute hypoxia induces an accumulation of ubiquitinated PKG1 in ovine fetal and newborn pulmonary artery smooth muscle cells. Such a modification was not evident in ovine fetal systemic (cerebral) artery smooth muscle cells. The accumulation of polyubiquitinated PKG1 observed after 4 hours of hypoxia was affected neither by the activation of PKG1 kinase activity with the cell-permeable cGMP analogue 8-bromo-cGMP, nor by its inhibition with DT-3 in fetal pulmonary artery smooth muscle cells. Ubiquitinated PKG1α was unable to bind the cGMP analogue 8-(2-aminoethyl)thioguanosine-3',5' (AET)-cGMP, a ligand for the unmodified protein. Inhibition of the proteasomal complex with MG132 led to the accumulation of polyubiquitinated PKG1 in normoxia, indicating the involvement of the ubiquitin-26S proteasomal system in degradation and clearance of this protein under normoxic conditions. The ubiquitinated PKG1 under hypoxic conditions, however, was not predominantly targeted for proteasomal degradation. Importantly, reoxygenation reversed the acute hypoxia-induced accumulation of ubiquitinated PKG1. Our results suggest that the PKG1 ubiquitination induced by acute hypoxia plays a unique role in the regulation of the pulmonary vascular smooth muscle cell vasoreactivity and relaxation mediated by the NO-cGMP-PKG1 pathway.
Collapse
Affiliation(s)
- Ramaswamy Ramchandran
- Department of Pediatrics, College of Medicine, University of Illinois at Chicago, 840 S. Wood St., M/C 856, Chicago, IL 60612, USA.
| | | | | | | | | | | |
Collapse
|
8
|
Abstract
The medical and pharmaceutical communities are facing a dire need for new druggable targets, while, paradoxically, the targets of some drugs that are in clinical use or development remain elusive. Many compounds have been found to be more promiscuous than originally anticipated, which can potentially lead to side effects, but which may also open up additional medical uses. As we move toward systems biology and personalized medicine, comprehensively determining small molecule-target interaction profiles and mapping these on signaling and metabolic pathways will become increasingly necessary. Chemical proteomics is a powerful mass spectrometry-based affinity chromatography approach for identifying proteome-wide small molecule-protein interactions. Here we will provide a critical overview of the basic concepts and recent advances in chemical proteomics and review recent applications, with a particular emphasis on kinase inhibitors and natural products.
Collapse
Affiliation(s)
- Uwe Rix
- Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.
| | | |
Collapse
|
9
|
Aye TT, Mohammed S, van den Toorn HWP, van Veen TAB, van der Heyden MAG, Scholten A, Heck AJR. Selectivity in enrichment of cAMP-dependent protein kinase regulatory subunits type I and type II and their interactors using modified cAMP affinity resins. Mol Cell Proteomics 2008; 8:1016-28. [PMID: 19119138 DOI: 10.1074/mcp.m800226-mcp200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
cAMP regulates cellular functions primarily by activating PKA. The involvement of PKAs in various signaling pathways occurring simultaneously in different cellular compartments necessitates stringent spatial and temporal regulation. This specificity is largely achieved by binding of PKA to protein scaffolds, whereby a distinct group of proteins called A kinase anchoring proteins (AKAPs) play a dominant role. AKAPs are a diverse family of proteins that all bind via a small PKA binding domain to the regulatory subunits of PKA. The binding affinities between PKA and several AKAPs can be different for different isoforms of the regulatory subunits of PKA. Here we employ a combination of affinity chromatography and mass spectrometry-based quantitative proteomics to investigate specificity in PKA-AKAP interactions. Three different immobilized cAMP analogs were used to enrich for PKA and its interacting proteins from several systems; HEK293 and RCC10 cells and rat lung and testis tissues. Stable isotope labeling was used to confidently identify and differentially quantify target proteins and their preferential binding affinity for the three different cAMP analogs. We were able to enrich all four isoforms of the regulatory subunits of PKA and concomitantly identify more than 10 AKAPs. A selective enrichment of the PKA RI isoforms could be achieved; which allowed us to unravel which AKAPs bind preferentially to the RI or RII regulatory domains of PKA. Of the twelve AKAPs detected, seven preferentially bound to RII, whereas the remaining five displayed at least dual specificity with a potential preference for RI. For some of these AKAPs our data provide the first insights into their specificity.
Collapse
Affiliation(s)
- Thin Thin Aye
- Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
10
|
Visser NFC, Scholten A, van den Heuvel RHH, Heck AJR. Surface-plasmon-resonance-based chemical proteomics: efficient specific extraction and semiquantitative identification of cyclic nucleotide-binding proteins from cellular lysates by using a combination of surface plasmon resonance, sequential elution and liquid chromatography-tandem mass spectrometry. Chembiochem 2008; 8:298-305. [PMID: 17206730 DOI: 10.1002/cbic.200600449] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Chemical proteomics is a powerful methodology for identifying the cellular targets of small molecules, however, it is biased towards abundant proteins. Therefore, quantitative strategies are needed to distinguish between specific and nonspecific interactions. Here, we explore the potential of the combination of surface plasmon resonance (SPR) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) as an alternative approach in chemical proteomics. We coupled cGMP molecules to the SPR chip, and monitored the binding and dissociation of proteins from a human lysate by using sequential elution steps and SPR. The eluted proteins were subsequently identified by LC-MS/MS. Our approach enabled the efficient and selective extraction of low-abundant cyclic-nucleotide-binding proteins such as cGMP-dependent protein kinase, and a quantitative assessment of the less- and nonspecific competitive binding proteins. The data show that SPR-based chemical proteomics is a promising alternative for the efficient specific extraction and quantitative identification of small-molecule-binding proteins from complex mixtures.
Collapse
Affiliation(s)
- Natasja F C Visser
- Department of Biomolecular Mass Spectrometry, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands
| | | | | | | |
Collapse
|
11
|
Abstract
The study of signal transduction provides fundamental information regarding the regulation of all biologic processes that support the normal function of life. Functional proteomics, a rapidly emerging discipline that aims to understand the expression, function and regulation of the entire set of proteins in a given cell type, tissue or organism, offers unprecedented opportunity for signal transduction research in terms of understanding cellular behavior and regulation at the systems level. Indeed, swift progress in the area of proteomics has demonstrated the major impact of proteomic approaches on signal transduction and biomedical research. In this review, recent and innovative applications of functional proteomics in determining changes in protein contents, modifications, activities and interactions underpinning signaling transduction pathways are discussed.
Collapse
Affiliation(s)
- Xiaodong Cheng
- Department of Pharmacology & Toxicology, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1031, USA.
| |
Collapse
|
12
|
Babu CVS, Lho DS, Yoo YS. Monitoring the neuropeptide metabolites by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. J Pharm Biomed Anal 2006; 40:136-41. [PMID: 16084048 DOI: 10.1016/j.jpba.2005.06.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2005] [Revised: 06/22/2005] [Accepted: 06/23/2005] [Indexed: 11/19/2022]
Abstract
The developments of bio-analytical methods for analyzing bioactive peptides are of paramount importance. Neuropeptides and their bioactive fragments play a vital role in the regulation of many biological processes and diseases. This paper presents the use of matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) method for monitoring neuropeptides along with their degradation products in plasma samples from cancer patients. The neuropeptides focused in this study were beta-endrophin, substance P, and bradykinin. The method involves the enzyme digestion of the neuroactive peptides followed by MALDI-MS sample preparation and subsequent acquisition of the MS spectral data. The mass spectral profile identifies most of the C-terminal and N-terminal peptides, and the mass accuracy was in the range of -1.68 to 1.46 Da with the mass spectrometer utilised. Analysis of the neuropeptide degradation patterns from the cancer patients were compared with the controls showed similar results. The study reveals that this approach can be used to identify the enzymatic digestion products of protein.
Collapse
Affiliation(s)
- C V Suresh Babu
- Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Republic of Korea
| | | | | |
Collapse
|