Isolation and Sequencing of Cu-, Fe-, and Zn-Binding Whey Peptides for Potential Neuroprotective Applications as Multitargeted Compounds
This study aims to isolate metal-binding peptides and synthesize promising amino acid sequences to potentially act as neuroprotective compounds in the future, targeting different mechanisms. Fractions of whey metal-binding peptides (Cu, Fe, and Zn) isolated by immobilized metal affinity chromatography showed different amino acid profiles according to the metal.
The Cu-binding peptides presented roughly twofold increase in the in vitro antioxidant, as assessed by oxygen radical absorbance capacity and anticholinesterase activities over the hydrolysate. This is probably because of the higher concentration of aromatic and basic residues, the latter being crucial for binding to the anionic sites of acetylcholinesterase.
Six peptide sequences were synthesized based on the metal-binding sites, molecular mass, hydrophobicity, and bioactivity probability.
Among the synthetic peptides, the VF dipeptide stood out both for its in vitro antioxidant and anticholinesterase activities. This peptide, as well as the fraction of Cu-binding peptides, should be further studied because it may act through different mechanisms related to neurodegenerative diseases, in addition to the chelation of the excess of metals in the central nervous system.
Scorpion sting: N-terminal fragment of proB-type natriuretic peptide as an early predictor of pediatric cardiotoxicity
Aim of the work: This prospective study was conducted to evaluate the clinical reliability of N-terminal fragment of proB-type natriuretic peptide (NT-proBNP) in identifying patients with cardiotoxicity in the early hours following scorpion sting.
Subjects and methods: This study involved 483 children aging between 2-17 years who were admitted to Minia University Poisoning Control Center from 1st January 2010 to 31st December 2019 with a history of scorpion sting, and on clinical evaluation symptoms were manifested. All subjects were clinically examined, investigated for NT-proBNP and CPK-MB on admission, 6 h and 24 h post-envenomation; and subjected to 24 h cardiac monitoring with periodic ECG every 6 h.
Results: Assessment of CPK-MB levels showed a significant increase in all moderate to severe cases 6 h post-envenomation. Assessment of NT-proBNP levels showed a significant increase in all moderate to severe cases on admission and 6 h post-envenomation. Moreover, there was a significant decrease in the NT-proBNP level after 24 h compared with that measured on admission. The sensitivity of NT-proBNP for the diagnosis of myocardial injury at hospital admission was significantly higher than that of CPK-MB.
Conclusion: NT-proBNP may be a valuable and sensitive laboratory biomarker to predict cardiotoxicity of scorpion sting in the early hours.
Investigating the role of chain and linker length on the catalytic activity of an H 2 production catalyst containing a β-hairpin peptide
Building on our recent report of an active H2 production catalyst [Ni(PPh2NProp-peptide)2]2+ (Prop = para-phenylpropionic acid, peptide (R10) = WIpPRWTGPR-NH2, p = D-proline and P2N = 1-aza-3,6-diphosphacycloheptane) that contains structured β-hairpin peptides, here we investigate how H2 production is effected by: (1) the length of the hairpin (eight or ten residues) and (2) limiting the flexibility between the peptide and the core complex by altering the length of the linker: para-phenylpropionic acid (three carbons) or para-benzoic acid (one carbon).
Reduction of the peptide chain length from ten to eight residues increases or maintains the catalytic current for H2 production for all complexes, suggesting a non-productive steric interaction at longer peptide lengths. While the structure of the hairpin appears largely intact for the complexes, NMR data are consistent with differences in dynamic behavior which may contribute to the observed differences in catalytic activity.
Molecular dynamics simulations demonstrate that complexes with a one-carbon linker have the desired effect of restricting the motion of the hairpin relative to the complex; however, the catalytic currents are significantly reduced compared to complexes containing a three-carbon linker as a result of the electron withdrawing nature of the -COOH group. These results demonstrate the complexity and interrelated nature of the outer coordination sphere on catalysis.
Description: Proprietary recombinant antigen expressed in E. coli and purified by chromatography. Individually pooled antigens shown to react with QC serum panel (multiple negative, borderline and positive sera) within defined reactivity range in Coxsackie-/Echovirus
Description: Proprietary recombinant antigen expressed in E. coli and purified by chromatography. Individually pooled antigens shown to react with QC serum panel (multiple negative, borderline and positive sera) within defined reactivity range in Coxsackie-/Echovirus
Description: Proprietary recombinant antigen expressed in E. coli and purified by chromatography. Individually pooled antigens shown to react with QC serum panel (multiple negative, borderline and positive sera) within defined reactivity range in Coxsackie-/Echovirus IgA, IgG and IgM ELISA.
Description: Proprietary recombinant antigen expressed in E. coli and purified by chromatography. Individually pooled antigens shown to react with QC serum panel (multiple negative, borderline and positive sera) within defined reactivity range in Coxsackie-/Echovirus IgA, IgG and IgM ELISA.
Helicobacter pylori urease large subunit antigen (RECOMBINANT)
Description: Recombinant Ross River virus antigen expressed in HEK293 cells as virus-like particles and purified by sucrose density gradients and precipitation. Virus-like particles were then solubilized in PBS containing 0.2% SDS to prevent aggregation of particles. The preparation is not particulate. Antigens in the preparation include Envelope proteins 1 and 2 and Nucleoprotein.
Description: Recombinant Ross River virus antigen expressed in HEK293 cells as virus-like particles and purified by sucrose density gradients and precipitation. Virus-like particles were then solubilized in PBS containing 0.2% SDS to prevent aggregation of particles. The preparation is not particulate. Antigens in the preparation include Envelope proteins 1 and 2 and Nucleoprotein.
Description: Lentivirus express Large T antigen of TSPyV (Trichodysplasia spinulosa-associated polyomavirus), containing RFP-Blasticidin dual selection.
Recent advances in seafood bioactive peptides and their potential for managing osteoporosis
Marine biodiversity provides a range of diverse biological resources, including seafoods that are rich in protein and a well-balanced amino acid composition. Previous studies have shown that peptides can improve bone formation and/or inhibit bone resorption, suggesting the potential for seafood bioactive peptides (SBPs) in development of food and pharmaceuticals for management of osteoporosis.
In this review, we provided an up-to-date overview of the anti-osteoporosis activity of SBPs and describe their underlying molecular mechanisms. We focus on SBPs’ development, broadening the scope and depth of research, as well as strengthening in vivo and clinical research.
In vitro cell cultures and in vivo animal osteoporosis models have demonstrated the potential for seafood-derived SBPs, including fish, mollusks, crustaceans, seaweed and microalgae, in preventing osteoporosis.
These peptides may act by activating the signaling pathways, such as BMP/Smads, MAPK, OPG/RANKL/RANK, and NF-κB, which are associated with modulation bone health.
Silver assisted stereo-directed assembly of branched peptide nucleic acids into four-point nanostars
Branched chiral peptide nucleic acids br(4S/R)-PNA with three arms of PNA-C4 strands were constructed on a central chiral core of 4(R/S)-aminoproline as the branching center. The addition of Ag+ triggered the self-assembly of branched PNAs through the formation of C-Ag+-C metallo base pairing of the three PNA C4 arms leading to non-covalent dendrimers, whose architecture is directed by the C4(R/S)-stereocenter of core 4-aminoproline.
The 4S-aminoprolyl core enabled the precise formation of four-pointed nanostars that was not realised with 4R-aminoprolyl or acyclic, achiral aminoethyl glycyl PNA cores. The dendritic assembly of 4 pointed nanostars exhibited net chirality of base stacks in CD spectra, while the base stack assembly from br(4R)-PNA 2 was overall achiral.
The results demonstrate that the silver assisted, 4S-aminoproline core stereo selective chiral assembly of branched PNAs manifests into nanostar morphology. The chiral branched PNAs open new vistas in the supramolecular organization of nucleic acids.
Peptide-Modified Nanoparticles for Tumor Targeting and Molecular Imaging
Nanoparticles hold great promise in tumor targeting and molecular imaging because they can co-deliver therapeutic drugs and imaging agents to the tumor site with a single entity. Nanoparticles modified with ligands against moieties overexpressed on tumor tissues have gained increasing attention due to their active targeting mechanisms.
Peptides are well suited for nanoparticle targeting modifications because they are small, easy to synthesize and typically non-immunogenic. Herein, we review the peptide-modified nanoparticles used for tumor targeting therapy and molecular imaging based on the classification of peptide-targeting ligands. The development of targeting peptides and nanoparticles will also be discussed.
