scholarly journals Cu(II) Binding Increases the Soluble Toxicity of Amyloidogenic Light Chains

2022 ◽  
Vol 23 (2) ◽  
pp. 950
Author(s):  
Rosaria Russo ◽  
Margherita Romeo ◽  
Tim Schulte ◽  
Martina Maritan ◽  
Luca Oberti ◽  
...  
Keyword(s):  
Copper Ions ◽  
Specific Binding ◽  
Isothermal Calorimetry ◽  
Blood Lead ◽  
Organ Damage ◽  
Light Chains ◽  
Copper Binding ◽  
C Elegans ◽  
Variable Domains

Light chain amyloidosis (AL) is caused by the aberrant overproduction of immunoglobulin light chains (LCs). The resulting abnormally high LC concentrations in blood lead to deposit formation in the heart and other target organs. Organ damage is caused not only by the accumulation of bulky amyloid deposits, but extensive clinical data indicate that circulating soluble LCs also exert cardiotoxic effects. The nematode C. elegans has been validated to recapitulate LC soluble toxicity in vivo, and in such a model a role for copper ions in increasing LC soluble toxicity has been reported. Here, we applied microscale thermophoresis, isothermal calorimetry and thermal melting to demonstrate the specific binding of Cu2+ to the variable domain of amyloidogenic H7 with a sub-micromolar affinity. Histidine residues present in the LC sequence are not involved in the binding, and yet their mutation to Ala reduces the soluble toxicity of H7. Copper ions bind to and destabilize the variable domains and induce a limited stabilization in this domain. In summary, the data reported here, elucidate the biochemical bases of the Cu2+-induced toxicity; moreover, they also show that copper binding is just one of the several biochemical traits contributing to LC soluble in vivo toxicity.

Role of albumin's copper binding site in copper uptake by mouse hepatocytes

1990 ◽  
Vol 258 (6) ◽  
pp. G988-G991 ◽  
Author(s):  
H. J. McArdle ◽  
S. M. Gross ◽  
D. M. Danks ◽  
A. G. Wedd
Keyword(s):  
Binding Site ◽  
Ternary Complex ◽  
Specific Binding ◽  
Specific Site ◽  
Copper Binding ◽  
Copper Uptake ◽  
Mouse Hepatocytes

It is possible, in vitro, to label albumin with copper either exclusively on the specific binding site or partly on the specific site and also on other sites by altering the pH at which the two ligands are mixed. Copper attached exclusively to the specific site is taken up more rapidly than copper attached to that site and others on albumin. The effect is proportional to the amount of copper on the specific site. Additional histidine stimulates uptake irrespective of the copper binding site on albumin. The effect is related to the histidine on position 3 of the albumin, since it is not seen when dog albumin is labeled under the same conditions. The data suggest that the cell recognizes and presumably binds the copper-albumin (CuAlb) complex but may preferentially recognize the ternary complex formed by CuAlb and histidine. We suggest that, in vivo, copper is bound mainly as the ternary complex and that the structure formed, presumably similar to that formed by a copper-histidine complex, is what is actually recognized by the cell. After binding, the albumin and histidine are released, possibly by a reduction step, and the copper is transported across the membrane. If the copper cannot be transported (as occurs when the cells are incubated at 4 degrees C), it blocks further binding of the ternary complex.

scholarly journals Multiple forms of copper (II) co-ordination occur throughout the disordered N-terminal region of the prion protein at pH 7.4

2006 ◽  
Vol 400 (3) ◽  
pp. 501-510 ◽  
Author(s):  
Mark A. Wells ◽  
Clare Jelinska ◽  
Laszlo L. P. Hosszu ◽  
C. Jeremy Craven ◽  
Anthony R. Clarke ◽  
...  
Keyword(s):  
Prion Protein ◽  
Tandem Repeats ◽  
Copper Ions ◽  
Equilibrium Dialysis ◽  
Terminal Region ◽  
Copper Binding ◽  
Binding Modes ◽  
Self Association

Although the physiological function of the prion protein remains unknown, in vitro experiments suggest that the protein may bind copper (II) ions and play a role in copper transport or homoeostasis in vivo. The unstructured N-terminal region of the prion protein has been shown to bind up to six copper (II) ions, with each of these ions co-ordinated by a single histidine imidazole and nearby backbone amide nitrogen atoms. Individually, these sites have micromolar affinities, which is weaker than would be expected of a true cuproprotein. In the present study, we show that with subsaturating levels of copper, different forms of co-ordination will occur, which have higher affinity. We have investigated the copper-binding properties of two peptides representing the known copper-binding regions of the prion protein: residues 57–91, which contains four tandem repeats of the octapeptide GGGWGQPH, and residues 91–115. Using equilibrium dialysis and spectroscopic methods, we unambiguously demonstrate that the mode of copper co-ordination in both of these peptides depends on the number of copper ions bound and that, at low copper occupancy, copper ions are co-ordinated with sub-micromolar affinity by multiple histidine imidazole groups. At pH 7.4, three different modes of copper co-ordination are accessible within the octapeptide repeats and two within the peptide comprising residues 91–115. The highest affinity copper (II)-binding modes cause self-association of both peptides, suggesting a role for copper (II) in controlling prion protein self-association in vivo.

In silico and In vivo Evaluation of Oxidative Stress Inhibitors Against Parkinson`s Disease using the C. elegans Model

2020 ◽  
Vol 23 (8) ◽  
pp. 814-826
Author(s):  
Pradeep Hanumanthappa ◽  
Arpitha Ashok ◽  
Inderjit Prakash ◽  
Carmel I. Priya ◽  
Julie Zinzala ◽  
...  
Keyword(s):  
Neuronal Death ◽  
Neurodegenerative Disorder ◽  
In Vivo Evaluation ◽  
Neuroprotective Effects ◽  
Ample Evidence ◽  
C Elegans ◽  
Rational Drug ◽  
Cullin 3 ◽  
Anti Oxidant

Background: Parkinson’s disease ranks second, after Alzheimer’s as the major neurodegenerative disorder, for which no cure or disease-modifying therapies exist. Ample evidence indicate that PD manifests as a result of impaired anti-oxidative machinery leading to neuronal death wherein Cullin-3 has ascended as a potential therapeutic target for diseases involving damaged anti-oxidative machinery. Objective: The design of target specific inhibitors for the Cullin-3 protein might be a promising strategy to increase the Nrf2 levels and to decrease the possibility of “off-target” toxic properties. Methods: In the present study, an integrated computational and wet lab approach was adopted to identify small molecule inhibitors for Cullin-3. The rational drug designing process comprised homology modeling and derivation of the pharmacophore for Cullin-3, virtual screening of Zinc natural compound database, molecular docking and Molecular dynamics based screening of ligand molecules. In vivo validations of an identified lead compound were conducted in the PD model of C. elegans. Results and Discussion: Our strategy yielded a potential inhibitor; (Glide score = -12.31), which was evaluated for its neuroprotective efficacy in the PD model of C. elegans. The inhibitor was able to efficiently defend against neuronal death in PD model of C. elegans and the neuroprotective effects were attributed to its anti-oxidant activities, supported by the increase in superoxide dismutase, catalase and the diminution of acetylcholinesterase and reactive oxygen species levels. In addition, the Cullin-3 inhibitor significantly restored the behavioral deficits in the transgenic C. elegans. Conclusion: Taken together, these findings highlight the potential utility of Cullin-3 inhibition to block the persistent neuronal death in PD. Further studies focusing on Cullin-3 and its mechanism of action would be interesting.

Correlation between in vitro and in vivo Data of Radiolabeled Peptide for Tumor Targeting

2019 ◽  
Vol 19 (12) ◽  
pp. 950-960
Author(s):  
Soghra Farzipour ◽  
Seyed Jalal Hosseinimehr
Keyword(s):  
Tumor Targeting ◽  
Single Photon ◽  
Specific Binding ◽  
Specific Interaction ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Mixed Effect ◽  
Radiolabeled Peptides

Tumor-targeting peptides have been generally developed for the overexpression of tumor specific receptors in cancer cells. The use of specific radiolabeled peptide allows tumor visualization by single photon emission computed tomography (SPECT) and positron emission tomography (PET) tools. The high affinity and specific binding of radiolabeled peptide are focusing on tumoral receptors. The character of the peptide itself, in particular, its complex molecular structure and behaviors influence on its specific interaction with receptors which are overexpressed in tumor. This review summarizes various strategies which are applied for the expansion of radiolabeled peptides for tumor targeting based on in vitro and in vivo specific tumor data and then their data were compared to find any correlation between these experiments. With a careful look at previous studies, it can be found that in vitro unblock-block ratio was unable to correlate the tumor to muscle ratio and the success of radiolabeled peptide for in vivo tumor targeting. The introduction of modifiers’ approaches, nature of peptides, and type of chelators and co-ligands have mixed effect on the in vitro and in vivo specificity of radiolabeled peptides.

Delivery Efficacy Differences of Intravenous and Intraperitoneal Injection of Exosomes: Perspectives from Tracking Dye Labeled and MiRNA Encapsulated Exosomes

2020 ◽  
Vol 17 (3) ◽  
pp. 186-194 ◽  
Author(s):  
Xueying Zhou ◽  
Zhelong Li ◽  
Wenqi Sun ◽  
Guodong Yang ◽  
Changyang Xing ◽  
...  
Keyword(s):  
Intraperitoneal Injection ◽  
Drug Delivery Vehicles ◽  
C Elegans ◽  
Administration Routes ◽  
In Vivo Distribution ◽  
Obesity Therapy ◽  
Delivery Vehicles ◽  
Visceral Adipose ◽  
Mirna Abundance

Background: Exosomes are cell-derived nanovesicles that play vital roles in intercellular communication. Recently, exosomes are recognized as promising drug delivery vehicles. Up till now, how the in vivo distribution of exosomes is affected by different administration routes has not been fully understood. Methods: In the present study, in vivo distribution of exosomes following intravenous and intraperitoneal injection approaches was systemically analyzed by tracking the fluorescence-labeled exosomes and qPCR analysis of C. elegans specific miRNA abundance delivered by exosomes in different organs. Results: The results showed that exosomes administered through tail vein were mostly taken up by the liver, spleen and lungs while exosomes injected intraperitoneally were more dispersedly distributed. Besides the liver, spleen, and lungs, intraperitoneal injection effectively delivered exosomes into the visceral adipose tissue, making it a promising strategy for obesity therapy. Moreover, the results from fluorescence tracking and qPCR were slightly different, which could be explained by systemic errors. Conclusion: Together, our study reveals that different administration routes cause a significant differential in vivo distribution of exosomes, suggesting that optimization of the delivery route is prerequisite to obtain rational delivery efficiency in detailed organs.

Human Fibronectin Extra-Domain B (EDB)-Specific Aptide (APTEDB) Radiolabelling with Technetium-99m as a Potent Targeted Tumour-Imaging Agent

2018 ◽  
Vol 18 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Mohsen Mohammadgholi ◽  
Nourollah Sadeghzadeh ◽  
Mostafa Erfani ◽  
Saeid Abediankenari ◽  
Seyed Mohammad Abedi ◽  
...  
Keyword(s):  
Radioligand Binding ◽  
Specific Binding ◽  
Specific Protein ◽  
Tumour Imaging ◽  
Specific Binding Ratio ◽  
Tumour Uptake ◽  
Technetium 99M ◽  
In Vivo Experiments ◽  
Human Fibronectin

Background: Human fibronectin extra-domain B (EDB) is particularly expressed during angiogenesis progression. It is, thus, a promising marker of tumour growth. Aptides are a novel class of peptides with high-affinity binding to specific protein targets. APTEDB is an antagonist-like ligand that especially interacts with human fibronectin EDB. Objective: This study was the first attempt in which the hydrazinonicotinamide (HYNIC)-conjugated APTEDB was labelled with technetium-99m (99mTc) as an appropriate radiotracer and tricine/EDDA exchange labeling. Methods: Radiochemical purity, normal saline, and serum stability were evaluated by HPLC and radio-isotope TLC scanner. Other examinations, such as protein-binding calculation, dissociation radioligand binding assay, and partition coefficient constant determination, were also carried out. The cellular-specific binding of 99mTc- HYNIC-conjugated APTEDB was assessed in two EDB-positive (U87MG) and EDB-negative (U373MG) cell lines. Bio-distribution was investigated in normal mice as well as in U87MG and U373MG tumour-bearing mice. Eventually, the radiolabelled APTEDB was used for tumour imaging using planar SPECT. Results: Radiolabelling was achieved with high purity (up to 97%) and accompanied by high solution (over 90% after overnight) and serum (80% after 2 hours) stability. The obtained cellular-specific binding ratio was greater than nine-fold. In-vivo experiments showed rapid blood clearance with mainly renal excretion and tumour uptake specificity (0.48±0.03% ID/g after 1h). The results of the imaging also confirmed considerable tumour uptake for EDB-positive cell line compared with the EDB-negative one. Conclusion: Aptides are considered to be a potent candidate for biopharmaceutical applications. They can be modified with imaging or therapeutic agents. This report shows the capability of 99mTc-HYNIC-APTEDB for human EDB-expressing tumours detection.

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