Boronic Acids as Bioorthogonal Probes for Site‐Selective Labeling of Proteins

Site-selective bioconjugation to native protein residues is a powerful tool for protein functionalization, with cysteine and lysine side chains being the most common points for attachment owing to their high nucleophilicity. We now report a strategy for histidine modification using thiophosphorodichloridate reagents that mimic post-translational histidine phosphorylation, enabling fast and selective labeling of protein histidines under mild conditions where various payloads can be introduced via copper-assisted alkyne-azide cycloaddition (CuAAC) chemistry. We establish that these reagents are particularly effective at covalent modification of His-tags, which are common motifs to facilitate protein purification, as illustrated by selective attachment of polyarginine cargoes to enhance the uptake of proteins into living cells. This work provides a starting point for probing and enhancing protein function using histidine-directed chemistry.

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Ruthenium-catalyzed site-selective C–H arylation of 2-pyridones and 1-isoquinolinones

Organic & Biomolecular Chemistry ◽

10.1039/c7ob01277b ◽

2017 ◽

Vol 15 (26) ◽

pp. 5457-5461 ◽

Cited By ~ 21

Author(s):

K. Anil Kumar ◽

Prakash Kannaboina ◽

Parthasarathi Das

Keyword(s):

Boronic Acids ◽

Directing Group ◽

Site Selective

An efficient Ru(ii)-catalyzed site-selective C–H arylation of 2-pyridones and 1-isoquinolinones with boronic acids by using pyridine as a directing group has been developed.

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Site-Selective Labeling of a Lysine Residue in Human Serum Albumin

Angewandte Chemie ◽

10.1002/ange.201405924 ◽

2014 ◽

Vol 126 (44) ◽

pp. 11977-11980 ◽

Cited By ~ 7

Author(s):

Shigehiro Asano ◽

James T. Patterson ◽

Thomas Gaj ◽

Carlos F. Barbas

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Lysine Residue ◽

Selective Labeling ◽

Site Selective

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Protein Conjugation with Triazolinediones: Switching from a General Tyrosine-Selective Labeling Method to a Highly Specific Tryptophan Bioconjugation Strategy

10.26434/chemrxiv.13739320 ◽

2021 ◽

Author(s):

Klaas Decoene ◽

Kamil Unal ◽

An Staes ◽

Kris Gevaert ◽

Johan M. Winne ◽

...

Keyword(s):

Unnatural Amino Acids ◽

Click Reaction ◽

Selective Labeling ◽

Site Specific ◽

Tyrosine Residues ◽

Tryptophan Residues ◽

Low Levels ◽

Almost All ◽

Site Selective ◽

Labeling Method

Selective labeling of tyrosine residues in peptides and proteins can be achieved via a 'tyrosine-click' reaction with triazolinedione reagents (TAD). We have found that tryptophan residues are in fact often also labeled with this reagent. This off-target labeling is only observed at very low levels in protein bioconjugation but remains under the radar due to the low relative abundance of tryptophan compared to tyrosines in natural proteins, and because of the low availability and accessibility of their nucleophilic positions at the solvent-exposed protein surface. Moreover, because TAD-Trp adducts are known to be readily thermoreversible, it can be challenging to detect these physiologically stable but thermally labile modifications using several MS/MS techniques. We have found that fully solvent-exposed tryptophan side chains are kinetically favored over tyrosines under almost all conditions, and this selectivity can even be further enhanced by modifying the pH of the aqueous buffer to effect selective Trp-labeling. This new site-selective bioconjugation method does not rely on unnatural amino acids and has been demonstrated for peptides and for recombinant proteins. Thus, the TAD-Tyr click reaction can be turned into a highly site-specific labeling method for tryptophan.

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Bioinspired Thiophosphorodichloridate Reagents for Chemoselective Histidine Bioconjugation

10.26434/chemrxiv.7250201.v1 ◽

2018 ◽

Author(s):

Shang Jia ◽

Christopher Chang

Keyword(s):

Protein Function ◽

Living Cells ◽

Covalent Modification ◽

Native Protein ◽

Selective Labeling ◽

Protein Residues ◽

Mild Conditions ◽

Starting Point ◽

Histidine Phosphorylation ◽

Site Selective

Site-selective bioconjugation to native protein residues is a powerful tool for protein functionalization, with cysteine and lysine side chains being the most common points for attachment owing to their high nucleophilicity. We now report a strategy for histidine modification using thiophosphorodichloridate reagents that mimic post-translational histidine phosphorylation, enabling fast and selective labeling of protein histidines under mild conditions where various payloads can be introduced via copper-assisted alkyne-azide cycloaddition (CuAAC) chemistry. We establish that these reagents are particularly effective at covalent modification of His-tags, which are common motifs to facilitate protein purification, as illustrated by selective attachment of polyarginine cargoes to enhance the uptake of proteins into living cells. This work provides a starting point for probing and enhancing protein function using histidine-directed chemistry.

Download Full-text

Protein Conjugation with Triazolinediones: Switching from a General Tyrosine-Selective Labeling Method to a Highly Specific Tryptophan Bioconjugation Strategy

10.26434/chemrxiv.13739320.v1 ◽

2021 ◽

Author(s):

Klaas Decoene ◽

Kamil Unal ◽

An Staes ◽

Kris Gevaert ◽

Johan M. Winne ◽

...

Keyword(s):

Unnatural Amino Acids ◽

Click Reaction ◽

Selective Labeling ◽

Site Specific ◽

Tyrosine Residues ◽

Tryptophan Residues ◽

Low Levels ◽

Almost All ◽

Site Selective ◽

Labeling Method

Selective labeling of tyrosine residues in peptides and proteins can be achieved via a 'tyrosine-click' reaction with triazolinedione reagents (TAD). We have found that tryptophan residues are in fact often also labeled with this reagent. This off-target labeling is only observed at very low levels in protein bioconjugation but remains under the radar due to the low relative abundance of tryptophan compared to tyrosines in natural proteins, and because of the low availability and accessibility of their nucleophilic positions at the solvent-exposed protein surface. Moreover, because TAD-Trp adducts are known to be readily thermoreversible, it can be challenging to detect these physiologically stable but thermally labile modifications using several MS/MS techniques. We have found that fully solvent-exposed tryptophan side chains are kinetically favored over tyrosines under almost all conditions, and this selectivity can even be further enhanced by modifying the pH of the aqueous buffer to effect selective Trp-labeling. This new site-selective bioconjugation method does not rely on unnatural amino acids and has been demonstrated for peptides and for recombinant proteins. Thus, the TAD-Tyr click reaction can be turned into a highly site-specific labeling method for tryptophan.

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Site-selective labeling at Cys302 of aldehyde dehydrogenase unveils a selective mitochondrial stain

Molecular BioSystems ◽

10.1039/c1mb05137g ◽

2011 ◽

Vol 7 (8) ◽

pp. 2375 ◽

Cited By ~ 5

Author(s):

Yun Kyung Kim ◽

Jin Kak Lee ◽

Jun-Seok Lee ◽

Chang No Yoon ◽

Young-Tae Chang

Keyword(s):

Aldehyde Dehydrogenase ◽

Selective Labeling ◽

Site Selective

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Site-Selective Labeling of Chromium(III) as a Quencher on DNA for Molecular Beacons

ChemPlusChem ◽

10.1002/cplu.201700361 ◽

2017 ◽

Vol 82 (9) ◽

pp. 1224-1230 ◽

Cited By ~ 4

Author(s):

Huan Ma ◽

Wang Li ◽

Wenhu Zhou ◽

Juewen Liu

Keyword(s):

Molecular Beacons ◽

Selective Labeling ◽

Site Selective

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