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Reddy SS, Pal S, Ghosh S, Prabhakaran EN. Hydrogen Bond Surrogate-Constrained Dynamic Antiparallel β-Sheets. Chembiochem 2021; 22:2111-2115. [PMID: 33751754 DOI: 10.1002/cbic.202100028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/05/2021] [Indexed: 11/06/2022]
Abstract
Antiparallel β-sheets are important secondary structures within proteins that equilibrate with random-coil states; however, little is known about the exact dynamics of this process. Here, the first dynamic β-sheet models that mimic this equilibrium have been designed by using an H-bond surrogate that introduces constraint and torque into a tertiary amide bond. 2D NMR data sufficiently reveal the structure, kinetics, and thermodynamics of the folding process, thereby leading the way to similar analysis in isolated biologically relevant β-sheets.
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Affiliation(s)
- Sravanthi S Reddy
- Department of Organic Chemistry, Indian Institution of Science, 560 012, Bangalore, Karnataka, India
| | - Sunit Pal
- Department of Organic Chemistry, Indian Institution of Science, 560 012, Bangalore, Karnataka, India
| | - Sudip Ghosh
- Department of Organic Chemistry, Indian Institution of Science, 560 012, Bangalore, Karnataka, India
| | - Erode N Prabhakaran
- Department of Organic Chemistry, Indian Institution of Science, 560 012, Bangalore, Karnataka, India
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Li C, Takahashi T, Shrestha T, Kinoshita E, Matsubara T, Matsumoto M, Maruyama H. 4',6-Diamidino-2-Phenylindole Distinctly Labels Tau Deposits. J Histochem Cytochem 2018; 66:737-751. [PMID: 30106598 DOI: 10.1369/0022155418793600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tau deposits have distinct biochemical characteristics and vary morphologically based on identification with tau antibodies and several chemical dyes. Here, we report 4',6-diamidino-2-phenylindole (DAPI)-positivity of tau deposits. Furthermore, we investigated the cause for this positivity. DAPI was positive in 3R/4R (3-repeat/4-repeat) tau deposits in Alzheimer's disease, myotonic dystrophy, and neurodegeneration with brain iron accumulation, and in 4R tau deposits in corticobasal degeneration, but negative in 4R tau deposits in frontotemporal dementia with parkinsonism-17 and progressive supranuclear palsy. The peak emission wavelength of DAPI after binding to a tau deposit was similar to that after binding to a nucleus. This DAPI-positivity was conspicuous at the optimum concentration of 2 μg/ml. DAPI-positivity was diminished after formic acid treatment, but preserved after nucleic acid elimination and phosphate moiety blocking. Our results suggest that staining with 2 μg/ml DAPI is a common but useful tool to differentially detect tau deposits in various tauopathies.
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Affiliation(s)
- Chengyu Li
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tetsuya Takahashi
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tejashwi Shrestha
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Eiji Kinoshita
- Department of Functional Molecular Science, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoyasu Matsubara
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.,Department of Neuropathology, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Masayasu Matsumoto
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.,Sakai City Medical Center, Sakai, Japan
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
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Mohammadi Sejoubsari R, Martinez AP, Kutes Y, Wang Z, Dobrynin AV, Adamson DH. “Grafting-Through”: Growing Polymer Brushes by Supplying Monomers through the Surface. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00183] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | | | | | - Zilu Wang
- Department
of Polymer Science, University of Akron, Akron, Ohio 44304, United States
| | - Andrey V. Dobrynin
- Department
of Polymer Science, University of Akron, Akron, Ohio 44304, United States
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Bonduelle C, Makni F, Severac L, Piedra-Arroni E, Serpentini CL, Lecommandoux S, Pratviel G. Smart metallopoly(l-glutamic acid) polymers: reversible helix-to-coil transition at neutral pH. RSC Adv 2016. [DOI: 10.1039/c6ra19753a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Coordination to Zn species can be reversibly used to control the helix-to-coil transition of synthetic poly(l-glutamic acid) polymers at a neutral pH of 7.
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Affiliation(s)
- Colin Bonduelle
- CNRS
- LCC (Laboratoire de Chimie de Coordination (UPR8241)
- Université de Toulouse
- F-31077 Toulouse
- France
| | - Fatma Makni
- CNRS
- LCC (Laboratoire de Chimie de Coordination (UPR8241)
- Université de Toulouse
- F-31077 Toulouse
- France
| | - Laura Severac
- CNRS
- LCC (Laboratoire de Chimie de Coordination (UPR8241)
- Université de Toulouse
- F-31077 Toulouse
- France
| | - Estefania Piedra-Arroni
- CNRS
- LCC (Laboratoire de Chimie de Coordination (UPR8241)
- Université de Toulouse
- F-31077 Toulouse
- France
| | - Charles-Louis Serpentini
- CNRS
- IMRCP (Laboratoire des Interactions Moléculaire et de la Réactivité Chimique et Photochimique)
- UMR 5623
- Université Paul Sabatier
- 31062 Toulouse
| | | | - Geneviève Pratviel
- CNRS
- LCC (Laboratoire de Chimie de Coordination (UPR8241)
- Université de Toulouse
- F-31077 Toulouse
- France
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