1
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Daus F, Xie X, Geyer A. The silica mineralisation properties of synthetic Silaffin-1A 1 ( synSil-1A 1). Org Biomol Chem 2022; 20:3387-3396. [PMID: 35362502 DOI: 10.1039/d2ob00390b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthetic monodisperse pentadecapeptide synSil-1A1 is a representative of the microdisperse mixture of the native silaffin natSil-1A1 produced by the diatom Cylindrotheca fusiformis. The octaphosphorylated zwitterionic synSil-1A1 is able to mineralise silica under slightly acidic conditions at pH 5.5, which is the physiologically relevant pH range assumed. Like the posttranslational modifications of the native silaffins, synSil-1A1 is functionalised on all four lysine and phosphorylated on all seven serine residues. We describe the synthesis of a trimethyl-δ-hydroxy-L-lysine building block, the incorporation of this choline-type amino acid in peptide synthesis and its phosphorylation, together with all further posttranslational modifications observed in the native silaffins. Quantitative structure-activity relationships from silicification experiments at high dilution reveal the unique mineralisation properties of the hyperphosphorylated peptide as a single substance and in interaction with long-chain polyamines (LCPA). Diffusion-ordered spectroscopy (DOSY) experiments reveal the formation of polyelectrolyte complexes (PEC) between synSil-1A1 and long-chain polyamines, which promotes the silicification process. The microdroplets have an overall balanced ratio of 100-150 cationic and the same number of anionic charges. The unique zwitterionic synSil-1A1 confirms the prevailing molecular model of biosilicification and validates it with quantitative data based on a single phosphopeptide species, avoiding the usual unphysiologically high concentrations of phosphate of many previous in vitro silicification experiments.
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Affiliation(s)
- Fabian Daus
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Xiulan Xie
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Armin Geyer
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
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2
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Daus F, Pfeifer E, Seipp K, Hampp N, Geyer A. The role of phosphopeptides in the mineralisation of silica. Org Biomol Chem 2020; 18:700-706. [DOI: 10.1039/c9ob02438g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We describe the synthesis of hyperphosphorylated peptides and the investigation of theirin vitrosilicification activity in combination with long-chain polyamines (LCPA) at high dilution and mildly acidic conditions.
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Affiliation(s)
- Fabian Daus
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Erik Pfeifer
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Kevin Seipp
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Norbert Hampp
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Armin Geyer
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
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3
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Shelton PMM, Weller CE, Chatterjee C. A Facile N-Mercaptoethoxyglycinamide (MEGA) Linker Approach to Peptide Thioesterification and Cyclization. J Am Chem Soc 2017; 139:3946-3949. [PMID: 28230996 DOI: 10.1021/jacs.6b13271] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The C-terminal electrophilic activation of peptides by α-thioesterification requires strongly acidic conditions or complex chemical manipulations, which ultimately limit functional group compatibility and broad utility. Herein, we report a readily accessible N-mercaptoethoxyglycinamide (MEGA) solid-phase linker for the facile synthesis of latent peptide α-thioesters. Incubating peptide-MEGA sequences with 2-mercaptoethanesulfonic acid at mildly acidic pH yielded α-thioesters that were directly used in NCL without purification. The MEGA linker yielded robust access to thioesters ranging in length from 4 to 35 amino acids, and greatly simplified the synthesis of cyclic peptides. Finally, the high utility of MEGA was demonstrated by the one-pot synthesis of a functional analog of the Sunflower Trypsin Inhibitor 1.
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Affiliation(s)
- Patrick M M Shelton
- Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
| | - Caroline E Weller
- Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
| | - Champak Chatterjee
- Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
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4
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Qvit N. Microwave-assisted synthesis of cyclic phosphopeptide on solid support. Chem Biol Drug Des 2014; 85:300-5. [PMID: 25042903 DOI: 10.1111/cbdd.12388] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/03/2014] [Accepted: 06/26/2014] [Indexed: 12/30/2022]
Abstract
Phosphopeptides are important tools for studying intracellular signal transduction events in vitro and in vivo and are also potential drugs due to their direct competition with phosphoprotein recognition elements. Cyclization has been demonstrated to improve peptide selectivity, metabolic stability, and bioavailability. However, cyclic phosphopeptide synthesis may not be straightforward due to the sterically hindered phosphorylated side-chain amino acid derivatives. One option to overcome this hurdle is to use microwave-assisted synthesis, which has been shown to increase efficiency and reduce synthesis time. Herein, a detailed protocol is provided for synthesizing cyclic phosphopeptides using automated microwave. The overall synthesis duration was reduced and yields increased compared with a manual conventional method. This method provides a general, fast and facile way to synthesize cyclic peptides, demonstrating the synthesis of cyclic phosphorylated peptides which are known to be among the most challenging to produce.
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Affiliation(s)
- Nir Qvit
- Department of Chemical and Systems Biology, School of Medicine, Stanford University, Stanford, CA, 94305-5174, USA
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5
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Lechner CC, Becker CFW. Modified silaffin R5 peptides enable encapsulation and release of cargo molecules from biomimetic silica particles. Bioorg Med Chem 2013; 21:3533-41. [PMID: 23643899 DOI: 10.1016/j.bmc.2013.04.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 03/27/2013] [Accepted: 04/03/2013] [Indexed: 11/18/2022]
Abstract
Biomimetic silica formation has attracted increasing interest over the last decade for numerous biotechnological applications due to the favorable mild reaction conditions. Inspired from silica biogenesis in diatoms, peptide variants derived from native silaffins have been used for silica formation in vitro. Here a generally applicable route for covalently linking a cargo molecule to the R5 silaffin peptide via a disulfide linkage is established. The peptide CG12AB, a peptide ligand of the epidermal growth factor receptor, was chosen as model. The ability of such silaffin-cargo conjugates to encapsulate the cargo molecule during silaffin-mediated silica precipitation is demonstrated. Cargo release from silica material under different conditions was analyzed. The results obtained here provide a rational basis for developing engineered R5 silaffin peptides into efficient tools for silica precipitation as well as for entrapment and release of cargo molecules under physiological conditions.
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Affiliation(s)
- Carolin C Lechner
- University of Vienna, Department of Chemistry, Institute of Biological Chemistry, Währinger Strasse 38, 1090 Vienna, Austria
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6
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Stawikowski M, Fields GB. Introduction to peptide synthesis. CURRENT PROTOCOLS IN PROTEIN SCIENCE 2012; Chapter 18:18.1.1-18.1.13. [PMID: 22851497 DOI: 10.1002/0471140864.ps1801s69] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A number of synthetic peptides are significant commercial or pharmaceutical products, ranging from the dipeptide sugar substitute aspartame to clinically used hormones such as oxytocin, adrenocorticotropic hormone, and calcitonin. This unit provides an overview of the field of synthetic peptides and proteins. It discusses selecting the solid support and common coupling reagents. Additional information is provided regarding common side reactions and synthesizing modified residues.
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Affiliation(s)
| | - Gregg B Fields
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida
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7
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PERICH JOHNW. Efficient solid phase synthesis of mixed Thr(P)-, Ser(P)- and Tyr(P)-containing phosphopeptides by “global”“phosphite-triester” phosphorylation*. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1992.tb01461.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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8
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Identification and Suppression of β-Elimination Byproducts Arising from the Use of Fmoc-Ser(PO3Bzl,H)-OH in Peptide Synthesis. Int J Pept Res Ther 2009. [DOI: 10.1007/s10989-008-9165-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Harris PWR, Williams GM, Shepherd P, Brimble MA. The Synthesis of Phosphopeptides Using Microwave-assisted Solid Phase Peptide Synthesis. Int J Pept Res Ther 2008. [DOI: 10.1007/s10989-008-9149-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Abstract
A number of synthetic peptides are significant commercial or pharmaceutical products, ranging from the dipeptide sugar-substitute aspartame to clinically used hormones, such as oxytocin, adrenocorticotropic hormone, and calcitonin. This unit provides an overview of the field of synthetic peptides and proteins, including their purification. It discusses selecting the solid support and common coupling reagents. Additional information is provided regarding common side reactions and synthesizing modified residues.
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11
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12
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Maletínskâ L, Neugebauer W, Parê MC, Pêrodin J, Pham D, Escher E. Lipid Masking and Reactivation of Angiotensin Analogues. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19960790723] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Virta P, Katajisto J, Niittymäki T, Lönnberg H. Solid-supported synthesis of oligomeric bioconjugates. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00704-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Albeiicio F, Chinchilla R, Dodsworth DJ, Nájera C. NEW TRENDS IN PEPTIDE COUPLING REAGENTS. ORG PREP PROCED INT 2001. [DOI: 10.1080/00304940109356592] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Kupihár Z, Kele Z, Tóth GK. The H-phosphonate approach to the synthesis of phosphopeptides on solid phase. Org Lett 2001; 3:1033-5. [PMID: 11277788 DOI: 10.1021/ol015591s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text]. Ammonium tert-butyl H-phosphonate was used for the phosphorylation of Tyr- and Ser-containing peptides synthesized by an Fmoc strategy. This reaction, leading to a monoprotected peptide phosphate, was found to be highly efficient and generally applicable. Moreover, the method employed avoids undesired side reactions during chain elongation (pyrophosphate formation and beta-elimination catalyzed by piperidine).
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Affiliation(s)
- Z Kupihár
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 8, Hungary
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16
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Abstract
Phosphorylation and dephosphorylation are key events in protein expression and regulation and in signal transduction. Phosphopeptides are very useful reagents for the study of these processes, and have been used to great advantage in the study of phosphatase substrate specificity, SH2 domain ligand specificity, and protein-protein interactions. Furthermore, the advent of cell-permeable peptide carriers, such as those from the antennapedia homeodomain and the HIV TAT transcription factor, has allowed the study of intracellular events, thus underscoring the utility of these reagents. In this paper we review methods for the synthesis of phosphopeptides with the emphasis on the preparation of phosphoamino acid building blocks.
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Affiliation(s)
- J S McMurray
- Department of Neuro-Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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17
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Kupihár Z, Váradi G, Monostori É, Tóth GK. Preparation of an asymmetrically protected phosphoramidite and its application in solid-phase synthesis of phosphopeptides. Tetrahedron Lett 2000. [DOI: 10.1016/s0040-4039(00)00615-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Perich JW, Ede NJ, Eagle S, Bray AM. Synthesis of phosphopeptides by the multipin method: Evaluation of coupling methods for the incorporation of Fmoc-Tyr(PO3Bzl,H)-OH, Fmoc-Ser(PO3Bzl,H)-OH and Fmoc-Thr(PO3Bzl,H)-OH. ACTA ACUST UNITED AC 1999. [DOI: 10.1007/bf02443622] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Lasting N-terminal phosphorylation of c-Jun and activation of c-Jun N-terminal kinases after neuronal injury. J Neurosci 1998. [PMID: 9651196 DOI: 10.1523/jneurosci.18-14-05124.1998] [Citation(s) in RCA: 259] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Transcription factor c-Jun is proposed to control neuronal cell death and survival, but its activation by N-terminal phosphorylation and the underlying activity of the c-Jun N-terminal kinases (JNKs) remain to be elucidated in the adult mammalian brain. We generated a polyclonal antiserum that specifically recognizes c-Jun phosphorylated at its serine 73 (S73) residue after UV irradiation of 3T3 cells. Disruption of the c-jun locus in 3T3 cells abolished this reaction, and retransfection of the human c-jun at the c-jun-/- background restored it. The phospho-c-Jun antiserum was used to visualize N-terminally phosphorylated c-Jun in the adult rat brain with cellular resolution. Prolonged c-Jun S73 phosphorylation was detected in affected neurons up to 5 d after transient occlusion of medial cerebral artery or up to 50 d after transection of central nerve fiber tracts. After cerebral ischemia-reperfusion, phosphorylation of c-Jun was linked with induced expression of Fas-ligand (APO-1, CD95-ligand), whose gene is a putative c-Jun/AP-1 target, and with terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) reactivity, a marker for apoptosis. After nerve fiber transection, however, lasting c-Jun phosphorylation occurred in axotomized neurons negative for Fas-ligand or TUNEL and regardless of degeneration or survival. In contrast to these lasting phosphorylation patterns, transient seizure activity by pentylenetetrazole provoked only a brief c-Jun phosphorylation and JNK activation. In extracts from ischemic or axotomized brain compartments, c-Jun phosphorylation correlated with enhanced long-term JNK activity, and in-gel kinase assays visualized proteins with sizes corresponding to JNK isoforms as the only c-Jun N-terminally phosphorylating enzymes. These results demonstrate that lasting c-Jun S73 phosphorylation and JNK activity are part of neuronal stress response after neurodegenerative disorders in the adult mammalian brain with Fas-ligand as a putative apoptotic effector.
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20
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Affiliation(s)
- F Albericio
- Department of Organic Chemistry, University of Barcelona, Spain
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21
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Hoffmann R, Hoffmann T, Tholey A, Schulte AC, Kalbitzer HR. Synthesis and NMR spectroscopy of peptides containing either phosphorylated or phosphonylated cis- or trans-4-hydroxy-L-proline. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1997; 49:163-73. [PMID: 9147312 DOI: 10.1111/j.1399-3011.1997.tb00611.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Many proteins are regulated by reversible O-glycosylation and O-phosphorylation. Whereas O-glycosylation of hydroxy-L-proline is common and well investigated, phosphorylation has not been proved so far in vivo, but this post-translational modification is entirely possible. As a first step to identify this phosphoamino acid, we describe both the syntheses of peptides phosphorylated at 4-hydroxy-L-proline and the 1H and 31P NMR parameters of these phosphopeptides. The model peptides were synthesized on solid-phase using Fmoc-strategy. Both natural isomers of 4-hydroxy-L-proline (containing the hydroxyl group in either the cis or trans position) were introduced without side-chain protection. All peptides were globally phosphorylated with O,O'-tert-butyl-N,N-diethylphosphoramidite on the solid phase and cleaved with trifluoroacetic acid. Additionally, we synthesized two classes of phosphonopeptides that mimic phosphopeptides, namely H- and methylphosphonopeptides. The NMR data were based on the model peptide Gly-Gly-Hyp-Ala, which is regarded as a typical random-coil sequence. The NMR parameters showed a significant influence of the phosphate group on the cis-trans isomerization of the Gly-Hyp bond, which may reflect a possible regulation of proteins by changing their local conformations. The 1H and 31P NMR parameters differed for each isomer, and were distinct from the parameters of phosphorylated serine, threonine and tyrosine. These known shifts can be used to identify both cis- and trans-O-phospho-4-hydroxy-L-proline in vivo.
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Affiliation(s)
- R Hoffmann
- University of the Saarland, Saarbrücken, Germany.
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22
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Fretz H. A practical dealkylation procedure for O,O-dimethyl-phosphotyrosyl-containing peptide-resins. ACTA ACUST UNITED AC 1997. [DOI: 10.1007/bf00127965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Shapiro G, Büchler D, Dalvit C, Frey P, Fernández MC, Gomez-Lor B, Pombo-Villar E, Stauss U, Swoboda R, Waridel C. Combined Fmoc-Alloc strategy for a general SPPS of phosphoserine peptides; preparation of phosphorylation-dependent tau antisera. Bioorg Med Chem 1997; 5:147-56. [PMID: 9043666 DOI: 10.1016/s0968-0896(96)00211-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A block method for the solid phase synthesis (SPPS) of serine phosphopeptides has been developed using a combination of Fmoc and Alloc strategies. Alloc-Ser[PO(OCH2CH CH2)2] OH2, prepared in a one pot procedure from Alloc-Ser-OH, was introduced at the N-terminus of a sequence prepared by standard Fmoc-SPPS. Global cleavage of the allyl ester based protecting groups, followed by coupling of a tripeptide fragment, led to the tau phosphopeptide, 1. Using tau phosphopeptides a series of phosphorylation state-dependent antisera to human tau protein have been raised. These antisera are valuable tools for studying the tau protein which is found in an abnormal, hyperphosphorylated form in Alzheimer's disease brain.
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Affiliation(s)
- G Shapiro
- Preclinical Research, Sandoz Pharma Ltd, Basel, Switzerland
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24
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Highly efficient solid-phase phosphopeptide synthesis using bis-(polyfluorophenyl) chlorophosphates: Preparation of serine-threonine protein phosphatase substrates. Tetrahedron Lett 1996. [DOI: 10.1016/0040-4039(96)01874-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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25
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Sakaguchi K, Roller PP, Appella E. Chemical synthesis and applications of phosphopeptides. GENETIC ENGINEERING 1996; 18:249-278. [PMID: 8785124 DOI: 10.1007/978-1-4899-1766-9_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- K Sakaguchi
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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26
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Liao J, Lowthert LA, Ku NO, Fernandez R, Omary MB. Dynamics of human keratin 18 phosphorylation: polarized distribution of phosphorylated keratins in simple epithelial tissues. J Biophys Biochem Cytol 1995; 131:1291-301. [PMID: 8522590 PMCID: PMC2120635 DOI: 10.1083/jcb.131.5.1291] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Phosphorylation of keratin polypeptides 8 and 18 (K8/18) and other intermediate filament proteins results in their reorganization in vitro and in vivo. In order to study functional aspects of human K18 phosphorylation, we generated and purified a polyclonal antibody (termed 3055) that specifically recognizes a major phosphorylation site (ser52) of human K18 but not dephosphorylated K18 or a ser52-->ala K18 mutant. Pulse-chase experiments followed by immunoprecipitation and peptide mapping of in vivo 32PO4-labeled K8/18 indicated that the overall phosphorylation turnover rate is faster for K18 versus K8, and that ser52 of K18 is a highly dynamic phosphorylation site. Isoelectric focusing of 32PO4 labeled K18 followed by immunoblotting with 3055 showed that the major phosphorylated K18 species contain ser52 phosphorylation but that some K18 molecules exist that are preferentially phosphorylated on K18 sites other than ser52. Immunoblotting of total cell lysates obtained from cells at different stages of the cell cycle showed that ser52 phosphorylation increases three to fourfold during the S and G2/M phases of the cell cycle. Immunofluorescence staining of cells at different stages of mitosis, using 3055 or other antibodies that recognize the total keratin pool, resulted in preferential binding of the 3055 antibody to the reorganized keratin fraction. Staining of human tissues or tissues from transgenic mice that express human K18 showed that the phospho-ser52 K18 species are located preferentially in the basolateral and apical domains in the liver and pancreas, respectively, but no preferential localization was noted in other simple epithelial organs examined. Our results support a model whereby phosphorylated intermediate filaments are localized in specific cellular domains depending on the tissue type and site(s) of phosphorylation. In addition, ser52 of human K18 is a highly dynamic phosphorylation site that undergoes modulation during the S and G2/M phases of the cell cycle in association with filament reorganization.
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Affiliation(s)
- J Liao
- VA Palo Alto Health Care System, California 94304, USA
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27
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Abstract
Protein phosphorylation plays a critical role in the regulation of cell growth and differentiation. There is considerable interest, therefore, in the facile synthesis of peptides that possess selectively phosphorylated residues for use as molecular probes in mechanistic studies of the biological consequences of phosphorylation. This work will review the various synthetic protocols used in the generation of phosphopeptides and will discuss their characterization by amino acid compositional analysis.
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Affiliation(s)
- S D Sanderson
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha 68198-6805, USA
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28
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Urge L, Otvos L. Orthogonal solid-phase synthesis of N-glycopeptides using backbone protection to eliminate aspartimide formation. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf00117956] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Hoffmann R, Wachs WO, Berger RG, Kalbitzer HR, Waidelich D, Bayer E, Wagner-Redeker W, Zeppezauer M. Chemical phosphorylation of the peptides GGXA (X = S, T, Y): an evaluation of different chemical approaches. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1995; 45:26-34. [PMID: 7775006 DOI: 10.1111/j.1399-3011.1995.tb01564.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An evaluation was made of the two methods most commonly used for phosphorylation of hydroxyamino acids in peptides, i.e. the tetrazole-catalysed phosphitylation by di-tert-butyl-N,N-diethylphosphoramidite followed by oxidation and the phosphorylation by dibenzylphosphochloridate. As model system the sequence GGXA (X = S, T, Y) was used which represents a random-coil sequence avoiding the influence on the reaction kinetics of secondary structure formation. In the case of serine- and threonine-containing peptides, both synthetic methods gave comparable yields of the desired phosphopeptides. The phosphorylation of tyrosine was achieved more favorably via the phosphoramidite method. However, phosphotyrosine peptides are most easily obtained by peptide synthesis using Fmoc-Tyr(PO3Me2)OH as building block. The dibenzylphosphochloridate method yields the expected phosphopeptides as the only peptide derivative and in addition, a great number of unidentified by-products which can be removed by ion-exchange chromatography. The phosphoramidite method consistently resulted in three peptide derivatives, i.e. the desired phosphopeptide, the phosphitylated peptide and a bridged derivative with two GGXA fragments linked through a phosphodiester bridge. The derivatives were characterised by RP and ion-exchange chromatography, 31P- and 1H-NMR spectroscopy, and ion-spray and electrospray mass spectrometry. Interestingly, even these mild ionisation techniques resulted in partial fragmentation. The observed fragmentation pathways seem to be a diagnostic tool for the identification of phosphorylation sites in peptides. Both the phosphorylated serine and threonine peptide lost phosphoric acid (98 mass units), the tyrosine peptide lost phenyl phosphate (174 mass units).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R Hoffmann
- Department of Biochemistry, University of Saarland, Saarbrücken, Germany
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30
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Otvos L, Feiner L, Lang E, Szendrei GI, Goedert M, Lee VM. Monoclonal antibody PHF-1 recognizes tau protein phosphorylated at serine residues 396 and 404. J Neurosci Res 1994; 39:669-73. [PMID: 7534834 DOI: 10.1002/jnr.490390607] [Citation(s) in RCA: 350] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The microtubule-associated protein tau is hyperphosphorylated in the paired helical filaments (PHFs) of Alzheimer's disease. Immunological and direct chemical studies have identified Ser396 and Ser404 as two of the phosphorylated sites. Previously, we have demonstrated, using synthetic tau peptides containing phosphorylated Ser396, that this site is recognized by the monoclonal antibody PHF-1. The present study extends this observation by showing that PHF-1 recognizes tau peptides containing either individually phosphorylated Ser396 or Ser404, but that there is a > 10-fold increase in the sensitivity of detection of tau peptides by PHF-1 when both serines are phosphorylated. The recognition of singly or doubly phosphorylated Ser396 and Ser404 in tau by PHF-1 can also be demonstrated in Chinese hamster ovary cells transfected with full-length wild-type tau constructs or mutant constructs with Ala substituted for Ser396 or Ser404. We conclude that the PHF-1 epitope contains both phosphorylated Ser396 and Ser404.
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Affiliation(s)
- L Otvos
- Wistar Institute, Philadelphia, PA 19104
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31
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Fabian H, Otvos L, Szendrei GI, Lang E, Mantsch HH. Tyrosine- versus serine-phosphorylation leads to conformational changes in a synthetic tau peptide. J Biomol Struct Dyn 1994; 12:573-9. [PMID: 7537044 DOI: 10.1080/07391102.1994.10508760] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
One of the major immunodominant epitopes of the paired helical filaments (PHF) of Alzheimer's disease is the peptide sequence GAEIVYKSPVVSGD (T3), comprising amino acids 389-402 of the microtubule-associated protein, tau, when it is phosphorylated at the first serine residue. While the corresponding anti-PHF monoclonal antibody recognizes the peptide phosphorylated at either serine, it does not recognize the tyrosine-phosphorylated peptide. Here we describe the effect of serine- versus tyrosine-phosphorylation on the conformation of a synthetic tau peptide. While adding a phosphate to the serine residue has practically no impact on the structure of the non-phosphorylated peptide, phosphorylation of the tyrosine results in considerable conformational changes.
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Affiliation(s)
- H Fabian
- Institute for Biochemistry, Humboldt University Berlin, Germany
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33
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Craig AG, Hoeger CA, Miller CL, Goedken T, Rivier JE, Fischer WH. Monitoring protein kinase and phosphatase reactions with matrix-assisted laser desorption/ionization mass spectrometry and capillary zone electrophoresis: comparison of the detection efficiency of peptide-phosphopeptide mixtures. BIOLOGICAL MASS SPECTROMETRY 1994; 23:519-28. [PMID: 7918694 DOI: 10.1002/bms.1200230810] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) and capillary zone electrophoresis (CZE) were evaluated for monitoring protein phosphatase and kinase reactions in vitro. Varying concentrations of peptide C (YIHLEKKYVRRDSG), peptide S (YLIEDNEYTARQGA) and kemptide (LARRSALG) mixed with their corresponding phosphorylated peptides, pC, pS and pkemptide, were analyzed. Comparison between the two techniques indicated that MALDI MS was less quantitative than CZE, showing a bias towards detection of the unphosphorylated peptide S and kemptide. In terms of sensitivity, the MALDI MS and CZE techniques are comparable. Protein kinase A phosphorylation of kemptide was monitored with both MALDI MS and CZE, whereas alkaline phosphatase dephosphorylation of pC could only be monitored with MALDI MS. The absence of inhibition with phosphatase or kinase buffers is a significant advantage of MALDI MS. In contrast to CZE, the MALDI spectra allow identification of the species analyzed by virtue of their mass. The results obtained emphasize the advantage of monitoring enzymatic reactions in buffer solutions using MALDI MS compared with CZE.
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Affiliation(s)
- A G Craig
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute, San Diego, CA 92138-9216
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34
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Gorbics L, Urge L, Otvos L. Comparative and optimized dabsyl-amino acid analysis of synthetic phosphopeptides and glycopeptides. J Chromatogr A 1994; 676:169-76. [PMID: 7921174 DOI: 10.1016/0021-9673(94)80459-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The optimal conditions for amino acid analysis of phosphopeptides and N-acetylglucosamine- and N-acetylgalactosamine-containing glycopeptides were investigated by dabsyl-Cl derivatization and reversed-phase high-performance liquid chromatographic separation. By comparing the chromatographic behaviour of the dabsylated phosphoamino acids and dabsylated aminosugars on three different columns, it appears that the mechanism of binding to the column is different for the two modified dabsyl derivatives. The acid sensitivities of sugar and phosphate groups were also investigated. We found that while the optimal hydrolysis conditions for phosphopeptide analysis are peptide sequence-dependent, there is generally an applicable condition for the highest recovery of glycopeptides. A 1-h gas-phase hydrolysis time seems to be appropriate for the majority of glycopeptides and 1.5 h is suitable for the majority of phosphopeptides. The analysis was extended to the successful verification of the presence of the N-acetylglucosamine and the N-acetylgalactosamine moieties when these sugars were incorporated as parts of a disaccharide side chain of glycopeptides.
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Affiliation(s)
- L Gorbics
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104-4268
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35
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Wakamiya T, Saruta K, Yasuoka JI, Kusumoto S. An Efficient Procedure for Solid-Phase Synthesis of Phosphopeptides by the Fmoc Strategy. CHEM LETT 1994. [DOI: 10.1246/cl.1994.1099] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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36
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Tegge W. Solid-phase syntheses of phosphorylated and thiophosphorylated peptides related to an EGFR sequence. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1994; 43:448-53. [PMID: 8070968 DOI: 10.1111/j.1399-3011.1994.tb00543.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The 13 amino acid EGFR-sequence AENAEYLRVAPQS-NH2 containing the in vivo autophosphorylated Tyr 1171, was synthesized by Fmoc continuous-flow SPPS with and without N-terminal Boc protection. In addition to the native sequence, peptides in which tyrosine was exchanged by serine and threonine were prepared. Global phosphorylation of the unprotected hydroxyl amino acids on the resin with di-tert-butyl-N,N-diethylphosphoramidite and 1H-tetrazole followed by in situ oxidation of the resulting phosphites with tert-butyl hydroperoxide or with dibenzoyl tetrasulfide resulted in the tyrosine-, serine- and threonine-phosphorylated and -thiophosphorylated sequences, respectively. The quality of the products after phosphorylation with N-terminal protection was better than without. Whereas the serine- and threonine-thiophosphate group was stable, tyrosine-thiophosphate turned out to be hydrolytically labile under acidic conditions. The rate of hydrolysis was determined with the tyrosine-thiophosphorylated model dipeptide Ac-Tyr-Gly-OH between pH 0.1 and 8. Hydrolysis was fastest at pH 3, with a half-time of 12.5 h at room temperature. The tyrosine-thiophosphate group was completely stable at pH 8.
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Affiliation(s)
- W Tegge
- Gesellschaft für Biotechnologische Forschung (GBF), Braunschweig, Germany
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37
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Shapiro G, Swoboda R, Stauss U. Fmoc solid phase synthesis of serine phosphopeptides via selective protection of serine and on resin phosphorylation. Tetrahedron Lett 1994. [DOI: 10.1016/s0040-4039(00)75985-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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39
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Gorbics L, Urge L, Lang E, Szendrei GI, Otvos L. Successful and Rapid Verification of the Presence of a Phosphate Group in Synthetic Phosphopeptides Using the Conditions of Standard Dabs-Cl Amino Acid Analysis. ACTA ACUST UNITED AC 1994. [DOI: 10.1080/10826079408013443] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Szendrei GI, Lee VM, Otvos L. Recognition of the minimal epitope of monoclonal antibody Tau-1 depends upon the presence of a phosphate group but not its location. J Neurosci Res 1993; 34:243-9. [PMID: 7680727 DOI: 10.1002/jnr.490340212] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The major constituent of the paired helical filaments (PHFs) of Alzheimer's disease is the abnormally phosphorylated form of the microtubule-associated protein, tau. Monoclonal antibody (mAb) Tau-1 is used extensively to stain normal human tau, and tau isolated from the brains of Alzheimer's disease patients after dephosphorylation. We used a panel of 6 synthetic peptides to localize the minimal epitope of Tau-1 between amino acids 192-204. All 4 serine residues within this fragment were later phosphorylated individually by chemical methods, and it was shown that none of the peptides carrying a single phosphate group were recognized by the antibody. The serines included those that are probably not transformed in AD and consequently, conclusions drawn about malfunctioning kinase activity, based on Tau-1 immunoreactivity, can be extremely misleading. The recognition was restored at a decreased level when one of the serines was replaced by an alanine residue. mAb AT8 was made by immunizing with the PHFs and was reported to recognize the same region of the protein in a phosphorylated form. AT8 did not, however, cross-react with any of the singly phosphorylated peptides, indicating that the recognition site of the two antibodies are not entirely complementary or the binding to AT8 needs multiple phosphorylation of the antigen. The abolished recognition of the phosphorylated peptides cannot be attributed to a conformational change due to phosphorylation, since all peptides exhibited reverse-turn secondary structures, as indicated by circular dichroism (CD) spectroscopy. Anti-tau mAbs may distinguish between phosphorylated and non-phosphorylated forms of epitopes regardless of the location of the phosphate group.
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Affiliation(s)
- G I Szendrei
- Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania 19104
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42
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Lang E, Szendrei GI, Lee VM, Otvos L. Immunological and conformation characterization of a phosphorylated immunodominant epitope on the paired helical filaments found in Alzheimer's disease. Biochem Biophys Res Commun 1992; 187:783-90. [PMID: 1382420 DOI: 10.1016/0006-291x(92)91264-q] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The immunological recognition pattern of one of the most commonly used monoclonal antibodies, PHF-1, which detects the paired helical filaments of Alzheimer's disease, exhibits a high degree of similarity with the recognition of a polyclonal antibody, anti-T3P, raised against a synthetic phosphopeptide, GAEIVYKS(Phospho)PVVSGD, corresponding to amino acids 389-402 of the microtubule-associated protein tau. A panel of 16 synthetic non-phosphorylated and phosphorylated peptides, excised from different regions of tau and peptide analogs thereof, were used to show that PHF-1 is indeed directed against the T3 fragment. Circular dichroism spectroscopy shows that the phosphorylated peptide exhibits a limited propensity to form intramolecular beta-pleated sheets, and alteration is found in the reverse-turn structure that dominates the middle section of the molecule. The shift in the turn-forming amino acids may also allow a stacking procedure, may interfere with microtubule assembly, and, consequently, may be accountable for deposit formation.
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Affiliation(s)
- E Lang
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104
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43
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Devault A, Fesquet D, Cavadore JC, Garrigues AM, Labbé JC, Lorca T, Picard A, Philippe M, Dorée M. Cyclin A potentiates maturation-promoting factor activation in the early Xenopus embryo via inhibition of the tyrosine kinase that phosphorylates cdc2. J Cell Biol 1992; 118:1109-20. [PMID: 1387401 PMCID: PMC2289581 DOI: 10.1083/jcb.118.5.1109] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We have produced human cyclin A in Escherichia coli and investigated how it generates H1 kistone kinase activity when added to cyclin-free extracts prepared from parthenogenetically activated Xenopus eggs. Cyclin A was found to form a major complex with cdc2, and to bind cdk2/Eg1 only poorly. No lag phase was detected between the time when cyclin A was added and the time when H1 histone kinase activity was produced in frog extracts, even in the presence of 2 mM vanadate, which blocks cdc25 activity. Essentially identical results were obtained using extracts prepared from starfish oocytes. We conclude that formation of an active cyclin A-cdc2 kinase during early development escapes an inhibitory mechanism that delays formation of an active cyclin B-cdc2 kinase. This inhibitory mechanism involves phosphorylation of cdc2 on tyrosine 15. Okadaic acid (OA) activated cyclin B-cdc2 kinase and strongly reduced tyrosine phosphorylation of cyclin B-associated cdc2, even in the presence of vanadate. 6-dimethylamino-purine, a reported inhibitor of serine-threonine kinases, suppressed OA-dependent activation of cyclin B-cdc2 complexes. This indicates that the kinase(s) which phosphorylate(s) cdc2 on inhibitory sites can be inactivated by a phosphorylation event, itself antagonized by an OA-sensitive, most likely type 2A phosphatase. We also found that cyclin B- or cyclin A-cdc2 kinases can induce or accelerate conversion of the cyclin B-cdc2 complex from an inactive into an active kinase. Cyclin B-associated cdc2 does not undergo detectable phosphorylation on tyrosine in egg extracts containing active cyclin A-cdc2 kinase, even in the presence of vanadate. We propose that the active cyclin A-cdc2 kinase generated without a lag phase from neo-synthesized cyclin A and cdc2 may cause a rapid switch in the equilibrium of cyclin B-cdc2 complexes to the tyrosine-dephosphorylated and active form of cdc2 during early development, owing to strong inhibition of the cdc2-specific tyrosine kinase(s). This may explain why early cell cycles are so rapid in many species.
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Affiliation(s)
- A Devault
- Centre National de la Recherche Scientifique UPR 8402, Montpellier, France
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44
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Otvos L, Urge L, Thurin J. Influence of different N- and O-linked carbohydrates on the retention times of synthetic peptides in reversed-phase high-performance liquid chromatography. J Chromatogr A 1992; 599:43-9. [PMID: 1618992 DOI: 10.1016/0021-9673(92)85457-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glycopeptides consisting of 6-19 amino acid residues and different mono- and disaccharides attached to single asparagine and serine residues were synthesized on solid-phase and were characterized by reversed-phase high-performance liquid chromatography and circular dichroism. It was shown that the decreased retention times due to glycosylation could be correlated with the increasing length of the sugar moiety. Phosphorylation of the same sequences reduced the retention times 1.6 times more than glycosylation with monosaccharides did. The binding to the column was dependent on the structure of the disaccharide when derivatized and glycosylated asparagine, the building block of N-glycopeptide syntheses was studied. However, this structural dependence of the elution times disappeared in the final glycopeptides. Although both glycosylation and phosphorylation resulted in altered secondary structure of the peptide backbone, it appears that the retention times reflect the increased hydrophilicity more strongly than induced conformational orientation on the surface of the bonded phase.
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Affiliation(s)
- L Otvos
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104
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45
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Lang E, Szendrei GI, Elekes I, Lee VM, Otvos L. Reversible beta-pleated sheet formation of a phosphorylated synthetic tau peptide. Biochem Biophys Res Commun 1992; 182:63-9. [PMID: 1731800 DOI: 10.1016/s0006-291x(05)80112-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Serine416 of human tau protein is believed to be phosphorylated in Alzheimer neurofibrillary tangles. We synthesized a fragment of tau, consisting of amino acids 408-421 in both non-phosphorylated and serine416-phosphorylated forms. Circular dichroism in a trifluoroethanol-water mixture indicated a beta-turn----beta-pleated sheet conformational transition upon phosphorylation. The beta-structure formation is intermolecular and can be inhibited by addition of Ca2+ ions or a phosphorylated tripeptide, but not with its non-phosphorylated analog. The presence of the phosphorylated tau peptide did not facilitate the formation of beta-pleated sheets of a phosphorylated neurofilament fragment. Multivalent cations induced a conformational transition of this phosphorylated neurofilament peptide, but the effect was less specific than the transition induced in the tau fragment, and it could also be reversed with the competing phosphorylated tripeptide.
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Affiliation(s)
- E Lang
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104
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46
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Fischer PM. Application of t-butyldimethylsilyl ethers of serine, threonine and tyrosine in peptide syntheshsis. Tetrahedron Lett 1992. [DOI: 10.1016/s0040-4039(00)60836-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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47
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Andrews DM, Kitchin J, Seale PW. Solid-phase synthesis of a range of O-phosphorylated peptides by post-assembly phosphitylation and oxidation. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1991; 38:469-75. [PMID: 1802864 DOI: 10.1111/j.1399-3011.1991.tb01528.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A completely general method for the O-phosphorylation of peptides of any given composition using solid-phase methodology is described. Peptides were assembled using Fmoc amino acid active esters, with base used for Fmoc deprotection. Unprotected amino acid side chain hydroxyl groups were phosphitylated and oxidised at the end of the assembly using bis(benzyloxy)(diisopropylamino)phosphine and tert.-butylhydroperoxide respectively. TFA was used for final deprotection of the amino acid side chains and for simultaneous cleavage from the resin. The synthesis of O-phosphopeptides of up to 15 residues in length is described.
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Affiliation(s)
- D M Andrews
- Medicinal Chemistry I, Glaxo Group Research, Greenford, Middlesex, UK
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48
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Kitas EA, Knorr R, Trzeciak A, Bannwarth W. Alternative Strategies for the Fmoc Solid-Phase Synthesis ofO4-Phospho-L-tyrosine-Containing Peptides. Helv Chim Acta 1991. [DOI: 10.1002/hlca.19910740621] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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49
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Solid-phase synthesis of glycopeptides: Glycosylation of resin-bound serine-peptides by 3,4,6-tri-o-acetyl-D-glucose-oxazoline. Tetrahedron Lett 1991. [DOI: 10.1016/s0040-4039(00)74264-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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50
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Zardeneta G, Chen DL, Weintraub ST, Klebe RJ. Synthesis of phosphotyrosyl-containing phosphopeptides by solid-phase peptide synthesis. Anal Biochem 1990; 190:340-7. [PMID: 1705399 DOI: 10.1016/0003-2697(90)90205-n] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The synthesis of phosphotyrosine-containing phosphopeptides using solid-phase peptide synthesis (SPPS) techniques is described. We present the synthesis of a Boc-phosphotyrosine derivative, which when used with modifications of the conventional SPPS protocol permits the incorporation of phosphotyrosine into synthetic peptides. The resulting phosphopeptides were authenticated by fast atom bombardment mass spectrometry, amino acid analysis, and phosphate assay. Alkaline phosphatase was found to dephosphorylate synthetic phosphopeptides at different rates, supporting the potential use of these synthetic substrates for studies of phosphoprotein phosphatases. Synthesis of a phosphopeptide using the described protocol has several advantages over the preparation of phosphopeptides via enzymatic phosphorylation.
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Affiliation(s)
- G Zardeneta
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284-7762
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