1
|
Observation of Intact and Proteolytically Cleaved Amyloid-Beta (1-40)-Oleuropein Noncovalent Complex at Neutral pH by Mass Spectrometry. Molecules 2021; 26:molecules26113261. [PMID: 34071573 PMCID: PMC8197984 DOI: 10.3390/molecules26113261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 11/16/2022] Open
Abstract
Mass spectrometry analyses carried out on mass spectrometers equipped with soft ionization sources demonstrated their utility in the assessment of the formation of noncovalent complexes and the localization of the binding sites. Direct analyses by mass spectrometry of the noncovalent complex formed in acidic and mildly acidic environments by amyloid beta (1–40) peptide and oleuropein have been previously described, and, in several studies, the absorption, metabolism, excretion, and the implications in the prevention and therapy of Alzheimer’s disease of oleuropein have been investigated. Our paper presents modifications of the method previously employed for noncovalent complex observation, namely, the amyloid beta (1–40) pretreatment, followed by an increase in the pH and replacement of the chemical environment from ammonium acetate to ammonium bicarbonate. The formation of noncovalent complexes with one or two molecules of oleuropein was detected in all chemical solutions used, and the amyloid beta (17–28) binding site was identified via proteolytic experiments using trypsin prior to and after noncovalent complex formation. Our results highlight the importance of further studies on the effect of oleuropein against amyloid beta aggregation.
Collapse
|
2
|
Ion L, Petre BA. Immuno-Affinity Mass Spectrometry: A Novel Approaches with Biomedical Relevance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1140:377-388. [DOI: 10.1007/978-3-030-15950-4_21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
3
|
Opuni KFM, Al-Majdoub M, Yefremova Y, El-Kased RF, Koy C, Glocker MO. Mass spectrometric epitope mapping. MASS SPECTROMETRY REVIEWS 2018; 37:229-241. [PMID: 27403762 DOI: 10.1002/mas.21516] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/23/2016] [Indexed: 06/06/2023]
Abstract
Mass spectrometric epitope mapping has become a versatile method to precisely determine a soluble antigen's partial structure that directly interacts with an antibody in solution. Typical lengths of investigated antigens have increased up to several 100 amino acids while experimentally determined epitope peptides have decreased in length to on average 10-15 amino acids. Since the early 1990s more and more sophisticated methods have been developed and have forwarded a bouquet of suitable approaches for epitope mapping with immobilized, temporarily immobilized, and free-floating antibodies. While up to now monoclonal antibodies have been mostly used in epitope mapping experiments, the applicability of polyclonal antibodies has been proven. The antibody's resistance towards enzymatic proteolysis has been of key importance for the two mostly applied methods: epitope excision and epitope extraction. Sample consumption has dropped to low pmol amounts on both, the antigen and the antibody. While adequate in-solution sample handling has been most important for successful epitope mapping, mass spectrometric analysis has been found the most suitable read-out method from early on. The rapidity by which mass spectrometric epitope mapping nowadays is executed outperforms all alternative methods. Thus, it can be asserted that mass spectrometric epitope mapping has reached a state of maturity, which allows it to be used in any mass spectrometry laboratory. After 25 years of constant and steady improvements, its application to clinical samples, for example, for patient characterization and stratification, is anticipated in the near future. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:229-241, 2018.
Collapse
Affiliation(s)
- Kwabena F M Opuni
- Proteome Center Rostock, University Medicine and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Mahmoud Al-Majdoub
- Proteome Center Rostock, University Medicine and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Yelena Yefremova
- Proteome Center Rostock, University Medicine and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Reham F El-Kased
- Microbiology and Immunology Faculty of Pharmacy, The British University in Egypt, Cairo, Egypt
| | - Cornelia Koy
- Proteome Center Rostock, University Medicine and Natural Science Faculty, University of Rostock, Rostock, Germany
| | - Michael O Glocker
- Proteome Center Rostock, University Medicine and Natural Science Faculty, University of Rostock, Rostock, Germany
| |
Collapse
|
4
|
Doulberis M, Kotronis G, Thomann R, Polyzos SA, Boziki M, Gialamprinou D, Deretzi G, Katsinelos P, Kountouras J. Review: Impact of Helicobacter pylori on Alzheimer's disease: What do we know so far? Helicobacter 2018; 23. [PMID: 29181894 DOI: 10.1111/hel.12454] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Helicobacter pylori has changed radically gastroenterologic world, offering a new concept in patients' management. Over time, more medical data gave rise to diverse distant, extragastric manifestations and interactions of the "new" discovered bacterium. Special interest appeared within the field of neurodegenerative diseases and particularly Alzheimer's disease, as the latter and Helicobacter pylori infection are associated with a large public health burden and Alzheimer's disease ranks as the leading cause of disability. However, the relationship between Helicobacter pylori infection and Alzheimer's disease remains uncertain. METHODS We performed a narrative review regarding a possible connection between Helicobacter pylori and Alzheimer's disease. All accessible relevant (pre)clinical studies written in English were included. Both affected pathologies were briefly analyzed, and relevant studies are discussed, trying to focus on the possible pathogenetic role of this bacterium in Alzheimer's disease. RESULTS Data stemming from both epidemiologic studies and animal experiments seem to be rather encouraging, tending to confirm the hypothesis that Helicobacter pylori infection might influence the course of Alzheimer's disease pleiotropically. Possible main mechanisms may include the bacterium's access to the brain via the oral-nasal-olfactory pathway or by circulating monocytes (infected with Helicobacter pylori due to defective autophagy) through disrupted blood-brain barrier, thereby possibly triggering neurodegeneration. CONCLUSIONS Current data suggest that Helicobacter pylori infection might influence the pathophysiology of Alzheimer's disease. However, further large-scale randomized controlled trials are mandatory to clarify a possible favorable effect of Helicobacter pylori eradication on Alzheimer's disease pathophysiology, before the recommendation of short-term and cost-effective therapeutic regimens against Helicobacter pylori-related Alzheimer's disease.
Collapse
Affiliation(s)
- Michael Doulberis
- Department of Internal Medicine, Bürgerspital Hospital, Solothurn, Switzerland
| | - Georgios Kotronis
- Department of Internal Medicine, Agios Pavlos General Hospital, Thessaloniki, Macedonia, Greece
| | - Robert Thomann
- Department of Internal Medicine, Bürgerspital Hospital, Solothurn, Switzerland
| | - Stergios A Polyzos
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Marina Boziki
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Dimitra Gialamprinou
- Department of Pediatrics, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Georgia Deretzi
- Department of Neurology, Papageorgiou General Hospital, Multiple Sclerosis Unit, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Panagiotis Katsinelos
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| | - Jannis Kountouras
- Department of Internal Medicine, Ippokration Hospital, Second Medical Clinic, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece
| |
Collapse
|
5
|
Prądzińska M, Behrendt I, Spodzieja M, Kołodziejczyk AS, Rodziewicz-Motowidło S, Szymańska A, Lundström SL, Zubarev RA, Macur K, Czaplewska P. Isolation and characterization of autoantibodies against human cystatin C. Amino Acids 2016; 48:2501-2518. [PMID: 27277188 DOI: 10.1007/s00726-016-2271-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/02/2016] [Indexed: 11/26/2022]
Abstract
Hereditary cystatin C amyloid angiopathy (HCCAA) is a severe neurodegenerative disorder related to the point mutation in cystatin C gene resulting in human cystatin C (hCC) L68Q variant. One of the potential immunotherapeutic approaches to HCCAA treatment is based on naturally occurring antibodies against cystatin C. A recent growing interest in autoantibodies, especially in the context of neurodegenerative diseases, emerges from their potential use as valuable diagnostic markers and for controlling protein aggregation. In this work, we present characteristics of natural anti-hCC antibodies isolated from the IgG fraction of human serum by affinity chromatography. The electrophoresis (1-D and 2-D) results demonstrated that the isolated NAbs are a polyclonal mixture, but their electrophoretic properties did not allow to classify the new autoantibodies to any particular type of IgG. The Fc-glycan status of the studied autoantibodies was assessed using mass spectrometry analysis. For the isolated NAbs, the epitopic fragments in hCC sequence were identified by MS-assisted proteolytic excision of the immune complex and compared with the ones predicted theoretically. The knowledge of hCC fragments binding to NAbs and other ligands may contribute to the search for new diagnostic methods for amyloidosis of different types and the search for their treatment.
Collapse
Affiliation(s)
- Martyna Prądzińska
- Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland
| | - Izabela Behrendt
- Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland
| | - Marta Spodzieja
- Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland
| | - Aleksandra S Kołodziejczyk
- Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland
| | - Sylwia Rodziewicz-Motowidło
- Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland
| | - Aneta Szymańska
- Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland
| | - Susanna L Lundström
- Division of Chemistry I, Head Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheelesvag 2, SE 17177, Stockholm, Sweden
| | - Roman A Zubarev
- Division of Chemistry I, Head Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheelesvag 2, SE 17177, Stockholm, Sweden
| | - Katarzyna Macur
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kładki 24, 80-822, Gdansk, Poland
| | - Paulina Czaplewska
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kładki 24, 80-822, Gdansk, Poland.
| |
Collapse
|
6
|
Petre BA. Affinity-mass spectrometry approaches for elucidating structures and interactions of protein-ligand complexes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 806:129-51. [PMID: 24952182 DOI: 10.1007/978-3-319-06068-2_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Affinity-based approaches in combination with mass spectrometry for molecular structure identification in biological complexes such as protein-protein, and protein-carbohydrate complexes have become popular in recent years. Affinity-mass spectrometry involves immobilization of a biomolecule on a chemically activated support, affinity binding of ligand(s), dissociation of the complex, and mass spectrometric analysis of the bound fraction. In this chapter the affinity-mass spectrometric methodologies will be presented for (1) identification of the epitope structures in the Abeta amyloid peptide, (2) identification of oxidative modifications in proteins such as nitration of tyrosine, (3) determination of carbohydrate recognition domains, and as (4) development of a biosensor chip-based mass spectrometric system for concomitant quantification and identification of protein-ligand complexes.
Collapse
Affiliation(s)
- Brînduşa Alina Petre
- Laboratory of Biochemistry, Department of Chemistry, Al. I. Cuza University of Iasi, Carol I Boulevard, No. 11, 700506, Iasi, Romania,
| |
Collapse
|
7
|
Al-Majdoub M, Koy C, Lorenz P, Thiesen HJ, Glocker MO. Mass spectrometric and peptide chip characterization of an assembled epitope: analysis of a polyclonal antibody model serum directed against the Sjøgren/systemic lupus erythematosus autoantigen TRIM21. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:651-659. [PMID: 23722955 DOI: 10.1002/jms.3208] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 03/19/2013] [Accepted: 03/24/2013] [Indexed: 06/02/2023]
Abstract
We demonstrate the development of a mass spectrometry-based epitope-mapping procedure in combination with Western blot analysis that works also with antigens that are insoluble in nondenaturing buffers consuming minute amounts of antigen (approximately 200 pmol) and antibody (approximately 15 pmol), respectively. A polyclonal anti-TRIM21 rabbit antibody serum is applied as a model serum for future patient analyses to set up the system. The major epitope that is recognized by the anti-TRIM21 serum spans the central TRIM21 region LQ-ELEKDEREQLRILGE-KE, showing that immunization with a 139-amino acid residue long peptide resulted in a 'monospecific' polyclonal antibody repertoire. Protein structure investigations, secondary structure predictions, and surface area calculations revealed that the best matching partial sequence to fulfill all primary and secondary structure requirements was the four amino acid spanning motif 'L-E-Q-L', which is present in both the sequential and the α-helical peptide conformation. Peptide chip analyses confirmed the mass spectrometric results and showed that the peptide chip platform is an appropriate method for displaying secondary structure-relying epitope conformations. As the same secondary structures are present in vivo, patient antibody screening, e.g., to identify subgroups of patients according to distinct epitope antibody reactivities, is feasible.
Collapse
Affiliation(s)
- M Al-Majdoub
- Proteome Center Rostock, University of Rostock, Rostock, Germany
| | | | | | | | | |
Collapse
|
8
|
Petre BA, Ulrich M, Stumbaum M, Bernevic B, Moise A, Döring G, Przybylski M. When is mass spectrometry combined with affinity approaches essential? A case study of tyrosine nitration in proteins. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1831-1840. [PMID: 22907170 DOI: 10.1007/s13361-012-0461-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 07/29/2012] [Accepted: 07/30/2012] [Indexed: 06/01/2023]
Abstract
Tyrosine nitration in proteins occurs under physiologic conditions and is increased at disease conditions associated with oxidative stress, such as inflammation and Alzheimer's disease. Identification and quantification of tyrosine-nitrations are crucial for understanding nitration mechanism(s) and their functional consequences. Mass spectrometry (MS) is best suited to identify nitration sites, but is hampered by low stabilities and modification levels and possible structural changes induced by nitration. In this insight, we discuss methods for identifying and quantifying nitration sites by proteolytic affinity extraction using nitrotyrosine (NT)-specific antibodies, in combination with electrospray-MS. The efficiency of this approach is illustrated by identification of specific nitration sites in two proteins in eosinophil granules from several biological samples, eosinophil-cationic protein (ECP) and eosinophil-derived neurotoxin (EDN). Affinity extraction combined with Edman sequencing enabled the quantification of nitration levels, which were found to be 8 % and 15 % for ECP and EDN, respectively. Structure modeling utilizing available crystal structures and affinity studies using synthetic NT-peptides suggest a tyrosine nitration sequence motif comprising positively charged residues in the vicinity of the NT- residue, located at specific surface- accessible sites of the protein structure. Affinities of Tyr-nitrated peptides from ECP and EDN to NT-antibodies, determined by online bioaffinity- MS, provided nanomolar K(D) values. In contrast, false-positive identifications of nitrations were obtained in proteins from cystic fibrosis patients upon using NT-specific antibodies, and were shown to be hydroxy-tyrosine modifications. These results demonstrate affinity- mass spectrometry approaches to be essential for unequivocal identification of biological tyrosine nitrations.
Collapse
Affiliation(s)
- Brînduşa-Alina Petre
- Steinbeis Research and Transfer Center for Biopolymer Analysis, Department of Chemistry, University of Konstanz, Konstanz, Germany
| | | | | | | | | | | | | |
Collapse
|
9
|
Śladewska A, Szymańska A, Kordalska M, Lewandowska A, Kołodziejczyk AS, Paraschiv G, Przybylski M, Czaplewska P. Identification of the epitope for anti-cystatin C antibody. J Mol Recognit 2011; 24:687-99. [DOI: 10.1002/jmr.1100] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
10
|
Juszczyk P, Paraschiv G, Szymanska A, Kolodziejczyk AS, Rodziewicz-Motowidlo S, Grzonka Z, Przybylski M. Binding epitopes and interaction structure of the neuroprotective protease inhibitor cystatin C with beta-amyloid revealed by proteolytic excision mass spectrometry and molecular docking simulation. J Med Chem 2009; 52:2420-8. [PMID: 19317448 DOI: 10.1021/jm801115e] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Human cystatin C (HCC) is a protease inhibitor with a propensity to form beta-amyloid (Abeta)-like fibrils and to coassociate with amyloidogenic proteins. Recently, a specific interaction between HCC and Abeta has been found. Here, we report the identification of the Abeta and HCC binding epitopes in the Abeta-HCC complex, using a combination of selective proteolytic excision and high resolution mass spectrometry. Proteolytic excision of Abeta(1-40) on sepharose-immobilized HCC and MALDI-MS identified the epitope Abeta(17-28). On immobilized Abeta(1-40), affinity MS of HCC fragments identified a specific C-terminal epitope, HCC(101-117). Binding specificities of both epitopes were ascertained by ELISA and surface plasmon resonance and by direct electrospray MS of the HCC-Abeta epitope peptide complexes. A structure model of the HCC-Abeta complex by molecular docking simulation showed full agreement with the identified Abeta and HCC epitopes. Inhibition studies in vitro revealed Abeta-fibril inhibiting activity of the HCC(101-117)-epitope. The Abeta-HCC interacting epitopes provide lead structures of neuroprotective inhibitors for AD and HCC amyloidosis therapy.
Collapse
Affiliation(s)
- Paulina Juszczyk
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | | | | | | | | | | | | |
Collapse
|
11
|
Perdivara I, Deterding LJ, Cozma C, Tomer KB, Przybylski M. Glycosylation profiles of epitope-specific anti-beta-amyloid antibodies revealed by liquid chromatography-mass spectrometry. Glycobiology 2009; 19:958-70. [PMID: 19318519 DOI: 10.1093/glycob/cwp038] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Alzheimer's disease (AD) is the most prevalent form of age-related neurodementia. The accumulation of beta-amyloid polypeptide (Abeta) in brain is generally believed to be a key event in AD. The recent discovery of physiological beta-amyloid autoantibodies represents a promising perspective for treatment and early diagnosis of AD. The mechanisms by which natural beta-amyloid autoantibodies prevent neurodegeneration are currently unknown. The aim of the present study was to analyze the N-linked glycosylation of a plaque-specific, monoclonal antibody (clone 6E10) relevant for immunotherapy of AD, in comparison with the glycosylation pattern of an Abeta autoantibody isolated from an IgG source. Liquid chromatography in combination with tandem mass spectrometry was used to analyze the glycopeptides generated by enzymatic degradation of the antibodies reduced and alkylated heavy chains. The oligosaccharide pattern of the 6E10 antibody shows primarily core-fucosylated biantennary complex structures and, to a low extent, tri- and tetragalactosyl glycoforms, with or without terminal sialic acids. The glycans associated with the serum anti-Abeta autoantibodies are of the complex, biantennary-type, fucosylated at the first N-acetyl glucosamine residue of the trimannosyl chitobiose core and contain zero to two galactose residues, and zero to one terminal sialic acid, with or without bisecting N-acetyl glucosamine. Glycosylation analysis of the Abeta-autoantibody performed at the peptide level revealed all four human IgG subclasses, with IgG(1) and IgG(2) as the dominant subclasses.
Collapse
Affiliation(s)
- Irina Perdivara
- Department of Chemistry, Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, University of Konstanz, 78457 Konstanz, Germany
| | | | | | | | | |
Collapse
|
12
|
Perdivara I, Deterding L, Moise A, Tomer KB, Przybylski M. Determination of primary structure and microheterogeneity of a beta-amyloid plaque-specific antibody using high-performance LC-tandem mass spectrometry. Anal Bioanal Chem 2008; 391:325-36. [PMID: 18369607 PMCID: PMC2842979 DOI: 10.1007/s00216-008-1941-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 01/29/2008] [Accepted: 02/05/2008] [Indexed: 01/08/2023]
Abstract
Using the bottom-up approach and liquid chromatography (LC) in combination with mass spectrometry, the primary structure and sequence microheterogeneity of a plaque-specific anti-beta-amyloid (1-17) monoclonal antibody (clone 6E10) was characterized. This study describes the extent of structural information directly attainable by a high-performance LC-tandem mass spectrometric method in combination with both protein database searching and de novo sequence determination. Using trypsin and chymotrypsin for enzymatic digestion, 95% sequence coverage of the light chain and 82% sequence coverage of the heavy chain of the 6E10 antibody were obtained. The primary structure determination of a large number of peptides from the antibody variable regions was obtained through de novo interpretation of the data. In addition, N-terminal truncations of the heavy chain were identified as well as low levels of pyroglutamic acid formation. Surprisingly, pronounced sequence microheterogeneities were determined for the CDR 2 region of the light chain, indicating that changes at the protein level derived from somatic hypermutation of the Ig V(L) genes in mature B-cells might contribute to unexpected structural diversity. Furthermore, the major glycoforms at the conserved heavy chain N-glycosylation site, Asn-292, were determined to be core-fucosylated, biantennary, complex-type structures containing zero to two galactose residues. [figure: see text]
Collapse
Affiliation(s)
- Irina Perdivara
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
- Mass Spectrometry Group, Laboratory of Structural Biology, National Institute of Health and Environmental Health Sciences (NIEHS/NIH), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Leesa Deterding
- Mass Spectrometry Group, Laboratory of Structural Biology, National Institute of Health and Environmental Health Sciences (NIEHS/NIH), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Adrian Moise
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Kenneth B. Tomer
- Mass Spectrometry Group, Laboratory of Structural Biology, National Institute of Health and Environmental Health Sciences (NIEHS/NIH), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Michael Przybylski
- Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| |
Collapse
|
13
|
Manea M, Przybylski M, Hudecz F, Mezö G. Design, structural, and immuno-analytical properties of antigenic bioconjugates comprising a β-amyloid-plaque specific epitope. Biopolymers 2008; 90:94-104. [DOI: 10.1002/bip.20916] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
14
|
Kountouras J, Gavalas E, Zavos C, Stergiopoulos C, Chatzopoulos D, Kapetanakis N, Gisakis D. Alzheimer's disease and Helicobacter pylori infection: Defective immune regulation and apoptosis as proposed common links. Med Hypotheses 2006; 68:378-88. [PMID: 16979298 DOI: 10.1016/j.mehy.2006.06.052] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 06/21/2006] [Indexed: 11/20/2022]
Abstract
Although degenerative diseases of the central nervous system, including Alzheimer's disease (AD), have an increasingly high impact on aged population their association with Helicobacter pylori (H. pylori) infection has not as yet been thoroughly researched. Current H. pylori infection appears to induce irregular humoral and cellular immune responses that, owing to the sharing of homologous epitopes (molecular mimicry), cross-react with components of nerves, thereby contributing and possibly perpetuating the apoptotic neural tissue damage observed in neurodegenerative diseases including AD. An association between AD and H. pylori infection has been recently addressed by two studies. A higher seropositivity for anti-H. pylori immunoglobulin G antibodies in 30 patients with AD than in 30 age-matched controls was reported in one study; this serological test, however, has limitations because it does not discriminate between current and old infections. In the other study, by introducing the histological method (the actual gold standard) for diagnosis of H. pylori infection, we reported a higher prevalence of H. pylori infection in 50 AD patients than in 30 anemic controls. This pathogen may influence the pathophysiology of AD by promoting platelet and platelet-leukocyte aggregation; releasing various pro-inflammatory and vasoactive substances; developing cross-mimicry with host antigens; producing reactive oxygen metabolites and circulating lipid peroxides; influencing the apoptotic process; and increasing, through induction of atrophic gastritis, homocysteine, which contributes to vascular disorders implicated in endothelial damage and neurodegeneration.
Collapse
Affiliation(s)
- Jannis Kountouras
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece.
| | | | | | | | | | | | | |
Collapse
|