Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 14 de 14
Filter
Add more filters










Publication year range
1.
Redox Biol ; 69: 102969, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38064764

ABSTRACT

Chemoproteomic profiling of sulfhydryl-containing proteins has consistently been an attractive research hotspot. However, there remains a dearth of probes that are specifically designed for sulfhydryl-containing proteins, possessing sufficient reactivity, specificity, distinctive isotopic signature, as well as efficient labeling and evaluation capabilities for proteins implicated in the regulation of redox homeostasis. Here, the specific selenium-containing probes (Se-probes) in this work displayed high specificity and reactivity toward cysteine thiols on small molecules, peptides and purified proteins and showed very good competitive effect of proteins labeling in gel-ABPP. We identified more than 6000 candidate proteins. In TOP-ABPP, we investigated the peptide labeled by Se-probes, which revealed a distinct isotopic envelope pattern of selenium in both the primary and secondary mass spectra. This unique pattern can provide compelling evidence for identifying redox regulatory proteins and other target peptides. Furthermore, our examiation of post-translational modification (PTMs) of the cysteine site residues showed that oxidation PTMs was predominantly observed. We anticipate that Se-probes will enable broader and deeper proteome-wide profiling of sulfhydryl-containing proteins, provide an ideal tool for focusing on proteins that regulate redox homeostasis and advance the development of innovative selenium-based pharmaceuticals.


Subject(s)
Cysteine , Selenium , Cysteine/metabolism , Sulfhydryl Compounds/chemistry , Peptides/metabolism , Proteome/metabolism , Oxidation-Reduction , Pharmaceutical Preparations
2.
Nat Commun ; 14(1): 7908, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38036533

ABSTRACT

Targeted proteasomal and autophagic protein degradation, often employing bifunctional modalities, is a new paradigm for modulation of protein function. In an attempt to explore protein degradation by means of autophagy we combine arylidene-indolinones reported to bind the autophagy-related LC3B-protein and ligands of the PDEδ lipoprotein chaperone, the BRD2/3/4-bromodomain containing proteins and the BTK- and BLK kinases. Unexpectedly, the resulting bifunctional degraders do not induce protein degradation by means of macroautophagy, but instead direct their targets to the ubiquitin-proteasome system. Target and mechanism identification reveal that the arylidene-indolinones covalently bind DCAF11, a substrate receptor in the CUL4A/B-RBX1-DDB1-DCAF11 E3 ligase. The tempered α, ß-unsaturated indolinone electrophiles define a drug-like DCAF11-ligand class that enables exploration of this E3 ligase in chemical biology and medicinal chemistry programs. The arylidene-indolinone scaffold frequently occurs in natural products which raises the question whether E3 ligand classes can be found more widely among natural products and related compounds.


Subject(s)
Biological Products , Cullin Proteins , Oxindoles , Ligands , Cullin Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Proteolysis , Proteasome Endopeptidase Complex/metabolism , Biological Products/pharmacology , Ubiquitination
3.
ACS Chem Biol ; 18(6): 1351-1359, 2023 06 16.
Article in English | MEDLINE | ID: mdl-37260364

ABSTRACT

S-sulfenylation of cysteine residues on proteins can effectively change protein structures and accordingly regulate their functions in vivo. Investigation of S-sulfenylation in different biological environments is thus vital for a systematic understanding of cellular redox regulation. In this work, a functional probe, biotin-benzoboroxole (Bio-ben), was designed for the detection of cysteine sulfenic acid (Cys-SOH). The performance of Bio-ben was characterized by small-molecule sulfenic acid, protein models, and proteome tests via mass spectra and western blotting. The results showed that Bio-ben was validated for cysteine sulfenic acid on proteins with good capture efficiency even at low concentrations. Compared with commonly used probes such as dimedone, the current probe has significantly shortened labeling time and exhibited comparable sensitivity. The proposed method provides a new approach for exploring S-sulfenylation in the oxidative modification of proteins and is helpful for related biological and clinical applications.


Subject(s)
Cysteine , Escherichia coli Proteins , Cysteine/chemistry , Sulfenic Acids/metabolism , Biotin/metabolism , Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Oxidation-Reduction
4.
Bioconjug Chem ; 33(6): 1131-1137, 2022 06 15.
Article in English | MEDLINE | ID: mdl-35576584

ABSTRACT

Owing to the encouraging pharmacological action and acceptable toxicity profile, Au(I) complexes have attracted growing interest in the application of disease treatment. In order to investigate their potential target proteins and related bioinformation, herein, we screened four Au(I) complexes and explored the binding proteins utilizing a competitive activity-based protein profiling (ABPP) strategy, including identification experiments and reactivity classification experiments, which offers a simple and robust method to identify the target proteins of Au(I) complexes. We quantified the target proteins of the four Au(I) complexes and found that most of proteins were associated with cancer. In addition, the newly Au(I)-binding proteins and biological gold-protein interaction pathways were exhibited. Furthermore, we estimated the correlation between target proteins of Au(I) complexes and various cancers, which will promote the development of the gold anticancer drugs.


Subject(s)
Gold , Proteins , Antineoplastic Agents/chemistry , Gold/chemistry , Humans , Neoplasms/drug therapy , Proteins/metabolism
5.
Org Lett ; 24(11): 2087-2092, 2022 Mar 25.
Article in English | MEDLINE | ID: mdl-35285642

ABSTRACT

The Pd(II)-catalyzed C-H bond activation/C-N bond cleavage annulation reaction of N-alkyoxyamide aryne is developed to synthesize 9,10-dihydrophenanthrenone derivatives. This reaction exhibited good functional group compatibility with yields up to 92%. Detailed mechanistic studies showed that the key to C-N bond cleavage is the formed eight-membered palladacycle intermediate undergoing nucleophilic addition to the carbonyl group, which provides a new and practical way for N-alkoxyamide directed C-H bond activation.

6.
Talanta ; 223(Pt 2): 121745, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33298269

ABSTRACT

The near-infrared fluorescence of gold nanoclusters stabilized with bovine serum albumin (BSA -AuNCs) centered at 675 nm could be enhanced by cysteine and then effectively quenched by copper ion (Cu2+), therefore, cysteine and copper ion could be detected in sequence. At "on" state, fluorescence enhancement of BSA-AuNCs is generated due to the reaction between cysteine and BSA-AuNCs, via filling the surface defect of gold nanoclusters, while Cu2+ can further oxidize the reductive sulfydryl of cysteine and interact with amino acids presented in the BSA chain, inducing gold nanoclusters to aggregate, thus causing "off" state with fluorescence quenching. Fluorescence switch of BSA-AuNCs can be used for cysteine and Cu2+ detection in mice brain with Alzheimer's disease (AD) in vitro, with fast response, high chemical stability and sensitivity. Besides, it was able to image the endogenous Cu2+ in liver and heart of AD mice in situ. The results are promising, especially in the framework of early diagnosis of Alzheimer's disease.


Subject(s)
Alzheimer Disease , Metal Nanoparticles , Alzheimer Disease/diagnostic imaging , Animals , Copper , Cysteine , Fluorescence , Gold , Mice , Serum Albumin, Bovine , Spectrometry, Fluorescence
7.
Chem Commun (Camb) ; 56(78): 11605-11608, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-32869786

ABSTRACT

Enantioselective synthesis of tetrahydroisoquinolines bearing an all-carbon quaternary stereogenic center, was achieved via asymmetric C-H activation with high enantioselectivities (up to 93% ee). Fair substrate tolerance was indicated throughout the scope investigation and no evident loss of enantioselectivity was exhibited in late-stage derivatization. This study provides incentives for the construction of diverse chiral isoquinoline derivatives, which are prevalent among pharmaceuticals, natural products, etc.

8.
Org Lett ; 22(16): 6394-6398, 2020 08 21.
Article in English | MEDLINE | ID: mdl-32806216

ABSTRACT

The first example of the Pd(II)-catalyzed enantioselective amination of aryl C-H bonds is reported. The key to the successful realization of this asymmetric catalytic transformation was the identification of mono-N-protected α-amino-O-methylhydroxamic acid (MPAHA) ligands, which promote reactivity under mild conditions and control enantioselectivity. The counteranions in the solvent medium, hexafluoroacetylacetate and acetate, were also found to play key roles in stereocontrol and reactivity enhancement.

9.
J Am Chem Soc ; 142(36): 15340-15348, 2020 Sep 09.
Article in English | MEDLINE | ID: mdl-32786750

ABSTRACT

The low n-doping efficiency of conjugated polymers with the molecular dopants limits their availability in electrical conductivity, thermoelectrics, and other electric applications. Recently, considerable efforts have focused on improving the ionization of dopants by modifying the structures of host polymers or n-dopants; however, the effect of ionized dopants on the electrical conductivity and thermoelectric performance of the polymers is still a puzzle. Herein, we try to reveal the role of molecular dopant cations on carrier transport through the systematic comparison of two n-dopants, TAM and N-DMBI-H. These two n-dopants exhibit various doping features with the polymer due to their different chemical structure characteristics. For instance, while doping, TAM negligibly perturbs the polymer backbone conformation and microstructural ordering; then after ionization, TAM cations possess weak π-backbone affinity but strong intrinsic affinity with side chains, which enables the doped system to screen the Coulomb potential spatially. Such doping features lead to high carrierization capabilities for TAM-doped polymers and further result in an excellent conductivity of up to 22 ± 2.5 S cm-1 and a power factor of over 80 µW m-1 K-2, which are significantly higher than the state of the art values of the common n-dopant N-DMBI-H. More importantly, this strategy has also proven to be widely applicable in other doped polymers. Our investigations indicate the vital role of dopant counterions in high electrical and thermoelectric performance polymers and also suggest that, without sacrificing Seebeck coefficients, high conductivities can be realized with precise regulation of the interaction between the cations and the host.

10.
Org Lett ; 20(20): 6530-6533, 2018 10 19.
Article in English | MEDLINE | ID: mdl-30299971

ABSTRACT

A palladium-catalyzed, amine-directed C(sp2)-H carbonylation of α,α-disubstituted benzylamine under 1 atm of CO for the facile synthesis of sterically hindered benzolactam has been developed. The key to success is the use of 2,2,6,6-tetramethyl-1-piperidinyloxy as the crucial sole oxidant. The synthetic utility of this transformation has been demonstrated by the first concise synthesis of the natural product spiropachysin-20-one.

11.
Chem Commun (Camb) ; 54(68): 9506-9509, 2018 Aug 21.
Article in English | MEDLINE | ID: mdl-30091742

ABSTRACT

Despite numerous studies on ebselen over the past decade, its cellular targets remain obscure. Here we synthesized a biotinylated ebselen probe (biotin-ebselen) and characterized ebselen-binding proteins via an efficient activity-based protein profiling (ABPP) method, which allowed for the robust identification of 462 targeted proteins in HeLa cells. This first work of global target profiling of ebselen will be helpful to re-design ebselen-based therapy appropriately in clinical trials.

12.
Angew Chem Int Ed Engl ; 56(48): 15436-15440, 2017 11 27.
Article in English | MEDLINE | ID: mdl-28985027

ABSTRACT

A novel radical [1,3]-nitrogen shift catalyzed by copper diacetate under an oxygen atmosphere (1 atm) has been developed for the construction of a diverse range of indole derivatives from α,α-disubstituted benzylamine. In this reaction, oxygen was used as a clean terminal oxidant, and water was produced as the only by-product. Five inert bonds were cleaved, and two C-N bonds and one C-C double bond were constructed in one pot during this transformation. This unique method demonstrated broad application protential for the late-stage modification of biologically active natural products and drugs. Mechanistic investigations indicate that a unique 4-exo-trig cyclization of an aminyl radical onto a phenyl ring is involved in the catalytic cycle.

13.
Org Biomol Chem ; 12(30): 5582-5, 2014 Aug 14.
Article in English | MEDLINE | ID: mdl-24963706

ABSTRACT

An iron-catalyzed aryldifluoromethylation of activated alkenes under mild reaction conditions has been developed, which is a rare example where a cosolvent is used to improve the reaction yield along with Fenton's reagent and thus provides an economic and green method for the synthesis of a variety of difluoromethylated oxindoles. Preliminary mechanistic investigations indicate a radical addition path.

14.
J Am Chem Soc ; 135(4): 1236-9, 2013 Jan 30.
Article in English | MEDLINE | ID: mdl-23305171

ABSTRACT

Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.


Subject(s)
Benzofurans/chemical synthesis , Organometallic Compounds/chemistry , Palladium/chemistry , Benzofurans/chemistry , Catalysis , Models, Molecular , Molecular Structure , Stereoisomerism
SELECTION OF CITATIONS
SEARCH DETAIL
...