An ortho-Iminoquinone Compound Reacts with Lysine Inhibiting Aggregation while Remodeling Mature Amyloid Fibrils.

ACS Chem Neurosci

Instituto de Bioquímica Médica Leopoldo de Meis, Programa de Biologia Estrutural, Universidade Federal do Rio de Janeiro , Rio de Janeiro 21941-590, Brazil.

Published: August 2017

Protein aggregation is a hallmark of several neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. It has been shown that lysine residues play a key role in the formation of these aggregates. Thus, the ability to disrupt aggregate formation by covalently modifying lysine residues could lead to the discovery of therapeutically relevant antiamyloidogenesis compounds. Herein, we demonstrate that an ortho-iminoquinone (IQ) can be utilized to inhibit amyloid aggregation. Using alpha-synuclein and Aβ as model amyloidogenic proteins, we observed that IQ was able to react with lysine residues and reduce amyloid aggregation. We also observed that IQ reacted with free amines within the amyloid fibrils preventing their dissociation and seeding capacity.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acschemneuro.7b00017DOI Listing

Publication Analysis

Top Keywords

lysine residues
12
amyloid fibrils
8
amyloid aggregation
8
ortho-iminoquinone compound
4
compound reacts
4
lysine
4
reacts lysine
4
lysine inhibiting
4
aggregation
4
inhibiting aggregation
4

Similar Publications

Elucidating the structure and function of a membrane-active plant protein domain using in silico mutagenesis.

Biochim Biophys Acta Biomembr

January 2025

Land and Food Systems, University of British Columbia, Vancouver, Canada; Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, Canada. Electronic address:

The Solanum tuberosum (common potato) plant specific insert (StPSI) is an antimicrobial protein domain that exhibits membrane-disrupting and membrane-fusing activity upon dimerization at acidic pH, activity proposed to involve electrostatic attraction and membrane anchoring mediated by specific positively-charged and conserved tryptophan residues, respectively. This study is the first to employ an in silico mutagenesis approach to clarify the structure-function relationship of a plant specific insert (PSI), where ten rationally-mutated StPSI variants were investigated using all-atom and coarse-grained molecular dynamics. The tryptophan (W) residue at position 18 (W18) of wild-type StPSI was predicted to confer structural flexibility to the dimer and mediate a partial separation of the assembled monomers upon bilayer contact, while residues including W77 and the lysine (K) residue at position 83 (K83) were predicted to stabilize secondary structure and influence association with the model membrane.

View Article and Find Full Text PDF

Despite the widespread use of MS for hydrogen/deuterium exchange measurements, no systematic, large-scale study has been conducted to compare the observed exchange rates in protein-derived, unstructured peptides measured by MS to the predicted exchange rates calculated from NMR-derived values and how neighboring residues and post-translational modifications influence those exchange rates. In this study, we sought to test the accuracy of predicted values by performing hydrogen exchange measurements on whole cell digests to generate an unbiased dataset of 563 unique peptides derived from naturally-occurring protein sequences. A remarkable 97% of observed exchange rates of peptides are within two-fold of predicted values.

View Article and Find Full Text PDF

Engineering high-activity crosslinked enzyme aggregates via SpyCatcher/SpyTag-mediated self-assembly.

Int J Biol Macromol

January 2025

College of Forestry, Northwest A&F University, No.3 Taicheng Road, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Economic Plant Resources Development and Utilization, Yangling, Shaanxi 712100, China. Electronic address:

Crosslinked Enzyme Aggregates (CLEAs) are favored for their operational stability and recyclability. However, the traditional CLEAs preparation may distort the enzyme's active site and reduce activity. Therefore, we developed a universally applicable crosslinked SpyCatcher scaffold system designed for the facile preparation of CLEAs.

View Article and Find Full Text PDF

Riboflavin-mediated ultraviolet photosensitive oxidation of beef myofibrillar proteins with different storage times.

Food Chem

January 2025

Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agricultural Product Processing, Ministry of Agriculture, Beijing 100193, China; Zibo Institute for Digital Agriculture and Rural Research, Zibo 255051, China. Electronic address:

The study was designed to investigate the mechanism of Riboflavin (RF)-mediated UVA photosensitive oxidation on beef myofibrillar proteins (MP) oxidized at different storage times. To elucidate the direct relationship between RF and protein oxidation, the mechanism of action was analyzed in terms of amino acid and side chain residues, protein structure, and protein oxidative metabolism. Oxidation of MP resulted in significant changes in the levels of carbonyls, sulfhydryls, Lysine, Arginine, Threonin, and Histidine.

View Article and Find Full Text PDF

The conserved K3 residue in the N-terminal region of Rab10 small GTPase is required for tubular endosome formation: N-terminal tagging causes Rab10 dysfunction.

J Cell Sci

January 2025

Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan.

Various N-terminal tags have often been used to identify the functions and localization of Rab small GTPases, but their impact on Rab proteins themselves has been poorly investigated. Here, we used a knockout (KO)-rescue approach to systematically evaluate the effect of N-terminal tagging of two Rabs, Rab10 and Rab27A, on Rab10-KO HeLa cells and Rab27A-deficient melanocytes (melan-ash cells), respectively. The results showed that all of the N-terminal-tagged Rab27A proteins mediated actin-based melanosome transport in the melan-ash cells, but none of the N-terminal-tagged Rab10 proteins fully rescued the defect in tubular endosome formation in the Rab10-KO cells.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!