scholarly journals Conjugation of Doxorubicin to siRNA Through Disulfide-based Self-immolative Linkers

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2714 ◽  
Author(s):  
Florian Gauthier ◽  
Jean-Rémi Bertrand ◽  
Jean-Jacques Vasseur ◽  
Christelle Dupouy ◽  
Françoise Debart

Co-delivery systems of siRNA and chemotherapeutic drugs have been developed as an attractive strategy to optimize the efficacy of chemotherapy towards cancer cells with multidrug resistance. In these typical systems, siRNAs are usually associated to drugs within a carrier but without covalent interactions with the risk of a premature release and degradation of the drugs inside the cells. To address this issue, we propose a covalent approach to co-deliver a siRNA-drug conjugate with a redox-responsive self-immolative linker prone to intracellular glutathione-mediated disulfide cleavage. Herein, we report the use of two disulfide bonds connected by a pentane spacer or a p-xylene spacer as self-immolative linker between the primary amine of the anticancer drug doxorubicin (Dox) and the 2′-position of one or two ribonucleotides in RNA. Five Dox-RNA conjugates were successfully synthesized using two successive thiol-disulfide exchange reactions. The Dox-RNA conjugates were annealed with their complementary strands and the duplexes were shown to form an A-helix sufficiently stable under physiological conditions. The enzymatic stability of Dox-siRNAs in human serum was enhanced compared to the unmodified siRNA, especially when two Dox are attached to siRNA. The release of native Dox and RNA from the bioconjugate was demonstrated under reducing conditions suggesting efficient linker disintegration. These results demonstrate the feasibility of making siRNA-drug conjugates via disulfide-based self-immolative linkers for potential therapeutic applications.

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 267
Author(s):  
Chen Jiao ◽  
Franziska Obst ◽  
Martin Geisler ◽  
Yunjiao Che ◽  
Andreas Richter ◽  
...  

Stimuli-responsive hydrogels have a wide range of potential applications in microfluidics, which has drawn great attention. Double cross-linked hydrogels are very well suited for this application as they offer both stability and the required responsive behavior. Here, we report the integration of poly(N-isopropylacrylamide) (PNiPAAm) hydrogel with a permanent cross-linker (N,N′-methylenebisacrylamide, BIS) and a redox responsive reversible cross-linker (N,N′-bis(acryloyl)cystamine, BAC) into a microfluidic device through photopolymerization. Cleavage and re-formation of disulfide bonds introduced by BAC changed the cross-linking densities of the hydrogel dots, making them swell or shrink. Rheological measurements allowed for selecting hydrogels that withstand long-term shear forces present in microfluidic devices under continuous flow. Once implemented, the thiol-disulfide exchange allowed the hydrogel dots to successfully capture and release the protein bovine serum albumin (BSA). BSA was labeled with rhodamine B and functionalized with 2-(2-pyridyldithio)-ethylamine (PDA) to introduce disulfide bonds. The reversible capture and release of the protein reached an efficiency of 83.6% in release rate and could be repeated over 3 cycles within the microfluidic device. These results demonstrate that our redox-responsive hydrogel dots enable the dynamic capture and release of various different functionalized (macro)molecules (e.g., proteins and drugs) and have a great potential to be integrated into a lab-on-a-chip device for detection and/or delivery.


2019 ◽  
Vol 400 (5) ◽  
pp. 575-587 ◽  
Author(s):  
Sérgio F. Sousa ◽  
Rui P.P. Neves ◽  
Sodiq O. Waheed ◽  
Pedro A. Fernandes ◽  
Maria João Ramos

Abstract Disulfide bonds play a critical role in a variety of structural and mechanistic processes associated with proteins inside the cells and in the extracellular environment. The thioredoxin family of proteins like thioredoxin (Trx), glutaredoxin (Grx) and protein disulfide isomerase, are involved in the formation, transfer or isomerization of disulfide bonds through a characteristic thiol-disulfide exchange reaction. Here, we review the structural and mechanistic determinants behind the thiol-disulfide exchange reactions for the different enzyme types within this family, rationalizing the known experimental data in light of the results from computational studies. The analysis sheds new atomic-level insight into the structural and mechanistic variations that characterize the different enzymes in the family, helping to explain the associated functional diversity. Furthermore, we review here a pattern of stabilization/destabilization of the conserved active-site cysteine residues presented beforehand, which is fully consistent with the observed roles played by the thioredoxin family of enzymes.


2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Yayoi Onda

Plants are unique among eukaryotes in having evolved organelles: the protein storage vacuole, protein body, and chloroplast. Disulfide transfer pathways that function in the endoplasmic reticulum (ER) and chloroplasts of plants play critical roles in the development of protein storage organelles and the biogenesis of chloroplasts, respectively. Disulfide bond formation requires the cooperative function of disulfide-generating enzymes (e.g., ER oxidoreductase 1), which generate disulfide bonds de novo, and disulfide carrier proteins (e.g., protein disulfide isomerase), which transfer disulfides to substrates by means of thiol-disulfide exchange reactions. Selective molecular communication between disulfide-generating enzymes and disulfide carrier proteins, which reflects the molecular and structural diversity of disulfide carrier proteins, is key to the efficient transfer of disulfides to specific sets of substrates. This review focuses on recent advances in our understanding of the mechanisms and functions of the various disulfide transfer pathways involved in oxidative protein folding in the ER, chloroplasts, and mitochondria of plants.


2020 ◽  
Vol 11 (48) ◽  
pp. 7603-7624
Author(s):  
Ismail Altinbasak ◽  
Mehmet Arslan ◽  
Rana Sanyal ◽  
Amitav Sanyal

This review provides an overview of synthetic approaches utilized to incorporate the thiol-reactive pyridyl-disulfide motif into various polymeric materials, and briefly highlights its utilization to obtain functional materials.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
He Wang ◽  
Wenwen Shi ◽  
Danning Zeng ◽  
Qiudi Huang ◽  
Jiacui Xie ◽  
...  

Abstract Background Mitochondria play a role in the occurrence, development, drug resistance, metastasis, and other functions of cancer and thus are a drug target. An acid-activated mitochondria-targeting drug nanocarrier with redox-responsive function was constructed in the present study. However, whether this vector can precisely delivery paclitaxel (PTX) to enhance therapeutic efficacy in drug-resistant lung cancer is unknown. Results Acid-cleavable dimethylmaleic anhydride (DA) was used to modify pluronic P85-conjugated mitochondria-targeting triphenylphosphonium (TPP) using disulfide bonds as intermediate linkers (DA-P85-SS-TPP and DA-P-SS-T). The constructed nanocarriers demonstrated enhanced cellular uptake and selective mitochondrial targeting at extracellular pH characteristic for a tumor (6.5) and were characterized by extended circulation in the blood. TPP promoted the targeting of the DA-P-SS-T/PTX nanomicelles to the mitochondrial outer membrane to decrease the membrane potential and ATP level, resulting in inhibition of P-glycoprotein and suppression of drug resistance and cancer metastasis. PTX was also rapidly released in the presence of high glutathione (GSH) levels and directly diffused into the mitochondria, resulting in apoptosis of drug-resistant lung cancer cells. Conclusions These promising results indicated that acid-activated mitochondria-targeting and redox-responsive nanomicelles potentially represent a significant advancement in cancer treatment. Graphic Abstarct


2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Alberto Guevara-Flores ◽  
Irene P. del Arenal ◽  
Guillermo Mendoza-Hernández ◽  
Juan Pablo Pardo ◽  
Oscar Flores-Herrera ◽  
...  

Mitochondrial thioredoxin-glutathione reductase was purified from larvalTaenia crassiceps(cysticerci). The preparation showed NADPH-dependent reductase activity with either thioredoxin or GSSG, and was able to perform thiol/disulfide exchange reactions. At25∘Cspecific activities were437  ±  27mU mg-1and840  ±  49mU mg-1with thioredoxin and GSSG, respectively. ApparentKmvalues were0.87  ±  0.04 μM,41  ±  6 μM and19  ±  10 μM for thioredoxin, GSSG and NADPH, respectively. Thioredoxin from eukaryotic sources was accepted as substrate. The enzyme reduced H2O2in a NADPH-dependent manner, although with low catalytic efficiency. In the presence of thioredoxin, mitochondrial TGR showed a thioredoxin peroxidase-like activity. All disulfide reductase activities were inhibited by auranofin, suggesting mTGR is dependent on selenocysteine. The reductase activity with GSSG showed a higher dependence on temperature as compared with the DTNB reductase activity. The variation of the GSSG- and DTNB reductase activities on pH was dependent on the disulfide substrate. Like the cytosolic isoform, mTGR showed a hysteretic kinetic behavior at moderate or high GSSG concentrations, but it was less sensitive to calcium. The enzyme was able to protect glutamine synthetase from oxidative inactivation, suggesting that mTGR is competent to contend with oxidative stress.


Open Biology ◽  
2011 ◽  
Vol 1 (3) ◽  
pp. 110010 ◽  
Author(s):  
Clive Metcalfe ◽  
Peter Cresswell ◽  
Laura Ciaccia ◽  
Benjamin Thomas ◽  
A. Neil Barclay

Redox conditions change in events such as immune and platelet activation, and during viral infection, but the biochemical consequences are not well characterized. There is evidence that some disulfide bonds in membrane proteins are labile while others that are probably structurally important are not exposed at the protein surface. We have developed a proteomic/mass spectrometry method to screen for and identify non-structural, redox-labile disulfide bonds in leucocyte cell-surface proteins. These labile disulfide bonds are common, with several classes of proteins being identified and around 30 membrane proteins regularly identified under different reducing conditions including using enzymes such as thioredoxin. The proteins identified include integrins, receptors, transporters and cell–cell recognition proteins. In many cases, at least one cysteine residue was identified by mass spectrometry as being modified by the reduction process. In some cases, functional changes are predicted (e.g. in integrins and cytokine receptors) but the scale of molecular changes in membrane proteins observed suggests that widespread effects are likely on many different types of proteins including enzymes, adhesion proteins and transporters. The results imply that membrane protein activity is being modulated by a ‘redox regulator’ mechanism.


2019 ◽  
Vol 294 (46) ◽  
pp. 17437-17450 ◽  
Author(s):  
Yuichi Yokochi ◽  
Kazunori Sugiura ◽  
Kazuhiro Takemura ◽  
Keisuke Yoshida ◽  
Satoshi Hara ◽  
...  

Thioredoxin (Trx) is a redox-responsive protein that modulates the activities of its target proteins mostly by reducing their disulfide bonds. In chloroplasts, five Trx isoforms (Trx-f, Trx-m, Trx-x, Trx-y, and Trx-z) regulate various photosynthesis-related enzymes with distinct target selectivity. To elucidate the determinants of the target selectivity of each Trx isoform, here we investigated the residues responsible for target recognition by Trx-f, the most well-studied chloroplast-resident Trx. As reported previously, we found that positively-charged residues on the Trx-f surface are involved in the interactions with its targets. Moreover, several residues that are specifically conserved in Trx-f (e.g. Cys-126 and Thr-158) were also involved in interactions with target proteins. The validity of these residues was examined by the molecular dynamics simulation. In addition, we validated the impact of these key residues on target protein reduction by studying (i) Trx-m variants into which we introduced the key residues for Trx-f and (ii) Trx-like proteins, named atypical Cys His-rich Trx 1 (ACHT1) and ACHT2a, that also contain these key residues. These artificial or natural protein variants could reduce Trx-f–specific targets, indicating that the key residues for Trx-f are critical for Trx-f–specific target recognition. Furthermore, we demonstrate that ACHT1 and ACHT2a efficiently oxidize some Trx-f–specific targets, suggesting that its target selectivity also contributes to the oxidative regulation process. Our results reveal the key residues for Trx-f–specific target recognition and uncover ACHT1 and ACHT2a as oxidation factors of their target proteins, providing critical insight into redox regulation of photosynthesis.


Sign in / Sign up

Export Citation Format

Share Document