Evidence map›Paper›PMID 34293440›Full record

ArticleProtein expression and purification2021

Purification and characterization of an amyloidogenic repeat domain from the functional amyloid Pmel17.

Dexter N Dean, Jennifer C Lee

Open access · greenAbstract read
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Article in Protein expression and purification, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
0.5field-weighted citation impact, top 37% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 7 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Dexter N DeanLaboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, United States.
Jennifer C LeeLaboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, United States. Electronic address: leej4@nhlbi.nih.gov.
National Institutes of Health · US

Funding

Mechanisms of Functional Amyloid FormationZIAHL006034 · NHLBI · NATIONAL HEART, LUNG, AND BLOOD INSTITUTE · PI LEE, JENNIFER · 2010 to 2021
$1.8M
Intramural NIH HHS ZIA HL006034
6 · The paper itself

Abstract

The pre-melanosomal protein (Pmel17) is a human functional amyloid that supports melanin biosynthesis within melanocytes. This occurs in the melanosome, a membrane-bound organelle with an acidic intraluminal pH. The repeat region of Pmel17 (RPT, residues 315-444) has been previously shown to form amyloid aggregates under acidic melanosomal conditions, but not under neutral cytosolic conditions, when expressed and purified using a C-terminal hexa-histidine tag (RPT-His). Given the importance of protonation states in RPT-His aggregation, we questioned whether the histidine tag influenced the pH-dependent behavior. In this report, we generated a tagless RPT by inserting a tobacco etch virus (TEV) protease recognition sequence (ENLYGQ(G/S)) immediately upstream of a native glycine residue at position 312 in Pmel17. After purification of the fusion construct using a histidine tag, cleavage with TEV protease generated a fully native RPT (nRPT) spanning resides 312-444. We characterized the aggregation of nRPT, which formed amyloid fibrils under acidic conditions (pH ≤ 6) but not at neutral pH. Characterizing the morphologies of nRPT aggregates using transmission electron microscopy revealed a pH-dependent maturation from short, curved structures at pH 4 to paired, rod-like fibrils at pH 6. This was accompanied by a secondary structural transition from mixed random coil/β-sheet at pH 4 to canonical β-sheet at pH 6. We also show that pre-formed nRPT fibrils undergo disaggregation upon dilution into pH 7 buffer. More broadly, this strategy can be utilized to generate native amyloidogenic domains from larger proteins by utilizing intrinsic N-terminal glycine or serine residues.

Indexed as

Amino Acid SequenceAmyloidEndopeptidasesFluorescent DyesGlycinegp100 Melanoma AntigenHistidineHumansHydrogen-Ion ConcentrationMelanosomesProtein AggregatesSerineTandem Mass SpectrometryAmyloidEndopeptidasesFluorescent DyesGlycinegp100 Melanoma AntigenHistidinePMEL protein, humanProtein AggregatesSerineTEV proteaseAggregationAmyloidDisaggregationTEMTryptophan fluorescence

Identifiers

PMID34293440
PMCPMC8403166
OpenAlexW3186548682

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.