56 research outputs found
Synthetic peptides blocking sars-cov-2 (covid-19), and compositions, methods and uses related thereto
Synthetic peptides blocking sars-cov-2 (covid-19), and compositions, methods and uses related thereto
The invention relates to the field of medicine and therapeutically active peptides, more specifically to the design of peptides that antagonise Angiotensin-Converting Enzyme-2 (ACE-2) interaction with the receptor binding spike protein of SARS-CoV-2. Provided is a peptidic compound comprising or consisting of an amino acid sequence selected from the following: IYALLENAEDYNLVN, SRDKHEEHEKENDRGQ, DKFNHEAEDLFYQSSLASWNYNT, IEEQAKTFLDKFQHEVEEIYWQS, QDKHEEDYQMYNKGDKED and IDENARSYIDKFQHDAEEMWYQ, or an amide, an ester or a salt thereof
Structural and biochemical insights of CypA and AIF interaction
The Cyclophilin A (CypA)/Apoptosis Inducing Factor (AIF) complex is implicated in the DNA degradation in response to various cellular stress conditions, such as oxidative stress, cerebral hypoxia-ischemia and traumatic brain injury. The pro-apoptotic form of AIF (AIF(Î1-121)) mainly interacts with CypA through the amino acid region 370-394. The AIF(370-394) synthetic peptide inhibits complex formation in vitro by binding to CypA and exerts neuroprotection in a model of glutamate-mediated oxidative stress. Here, the binding site of AIF(Î1-121) and AIF(370-394) on CypA has been mapped by NMR spectroscopy and biochemical studies, and a molecular model of the complex has been proposed. We show that AIF(370-394) interacts with CypA on the same surface recognized by AIF(Î1-121) protein and that the region is very close to the CypA catalytic pocket. Such region partially overlaps with the binding site of cyclosporin A (CsA), the strongest catalytic inhibitor of CypA. Our data point toward distinct CypA structural determinants governing the inhibitor selectivity and the differential biological effects of AIF and CsA, and provide new structural insights for designing CypA/AIF selective inhibitors with therapeutic relevance in neurodegenerative diseases
Relevance of AIF/CypA Lethal Pathway in SH-SY5Y Cells Treated with Staurosporine
The AIF/CypA complex exerts a lethal activity in several rodent models of acute brain
injury. Upon formation, it translocates into the nucleus of cells receiving apoptotic stimuli, inducing
chromatin condensation, DNA fragmentation, and cell death by a caspaseâindependent mechanism.
Inhibition of this complex in a model of glutamateâinduced cell death in HTâ22 neuronal cells by an
AIF peptide (AIF(370â394)) mimicking the binding site on CypA, restores cell survival and prevents
brain injury in neonatal mice undergoing hypoxiaâischemia without apparent toxicity. Here, we
explore the effects of the peptide on SHâSY5Y neuroblastoma cells stimulated with staurosporine
(STS), a cellular model widely used to study Parkinsonâs disease (PD). This will pave the way to
understanding the role of the complex and the potential therapeutic efficacy of inhibitors in PD. We
find that AIF(370â394) confers resistance to STSâinduced apoptosis in SHâSY5Y cells similar to that
observed with CypA silencing and that the peptide works on the AIF/CypA translocation pathway
and not on caspases activation. These findings suggest that the AIF/CypA complex is a promising
target for developing novel therapeutic strategies against PD
Design, Optimization, and Structural Characterization of an Apoptosis-Inducing Factor Peptide Targeting Human Cyclophilin A to Inhibit Apoptosis Inducing Factor-Mediated Cell Death
Blocking the interaction between the apoptosis-inducing factor (AIF) and cyclophilin A (CypA) by the AIF fragment AIF(370-394) is protective against glutamate-induced neuronal cell death and brain injury in mice. Starting from AIF(370-394), we report the generation of the disulfide-bridged and shorter variant AIF(381-389) and its structural characterization by nuclear magnetic resonance (NMR) in the free and CypA-bound state. AIF(381-389) in both the free and bound states assumes a β-hairpin conformation similar to that of the fragment in the AIF protein and shows a highly reduced conformational flexibility. This peptide displays a similar in vitro affinity for CypA, an improved antiapoptotic activity in cells and an enhanced proteolytic stability compared to the parent peptide. The NMR-based 3D model of the AIF(381-389)/CypA complex provides a better understanding of the binding hot spots on both the peptide and the protein and can be exploited to design AIF/CypA inhibitors with improved pharmacokinetic and pharmacodynamics features
Interleukin 6 reduces vascular smooth muscle cell apoptosis via Prep1 and is associated with aging
n/
Targeting of PED/PEA-15 Molecular Interaction with Phospholipase D1 Enhances Insulin Sensitivity in Skeletal Muscle Cells
Phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15) is overexpressed in several tissues of individuals affected by type 2 diabetes. In intact cells and in transgenic animal models, PED/PEA-15 overexpression impairs insulin regulation of glucose transport, and this is mediated by its interaction with the C-terminal D4 domain of phospholipase D1 (PLD1) and the consequent increase of protein kinase C-alpha activity. Here we show that interfering with the interaction of PED/PEA-15 with PLD1 in L6 skeletal muscle cells overexpressing PED/PEA-15 (L6(PED/PEA-15)) restores insulin sensitivity. Surface plasmon resonance and ELISA-like assays show that PED/PEA-15 binds in vitro the D4 domain with high affinity (K(D) = 0.37 +/- 0.13 mum), and a PED/PEA-15 peptide, spanning residues 1-24, PED-(1-24), is able to compete with the PED/PEA-15-D4 recognition. When loaded into L6(PED/PEA-15) cells and in myocytes derived from PED/PEA-15-overexpressing transgenic mice, PED-(1-24) abrogates the PED/PEA-15-PLD1 interaction and reduces protein kinase C-alpha activity to levels similar to controls. Importantly, the peptide restores insulin-stimulated glucose uptake by approximately 70%. Similar results are obtained by expression of D4 in L6(PED/PEA-15). All these findings suggest that disruption of the PED/PEA-15-PLD1 molecular interaction enhances insulin sensitivity in skeletal muscle cells and indicate that PED/PEA-15 as an important target for type 2 diabetes
Recent Applications of Retro-Inverso Peptides
Natural and de novo designed peptides are gaining an ever-growing interest as drugs against several diseases. Their use is however limited by the intrinsic low bioavailability and poor stability. To overcome these issues retro-inverso analogues have been investigated for decades as more stable surrogates of peptides composed of natural amino acids. Retro-inverso peptides possess reversed sequences and chirality compared to the parent molecules maintaining at the same time an identical array of side chains and in some cases similar structure. The inverted chirality renders them less prone to degradation by endogenous proteases conferring enhanced half-lives and an increased potential as new drugs. However, given their general incapability to adopt the 3D structure of the parent peptides their application should be careful evaluated and investigated case by case. Here, we review the application of retro-inverso peptides in anticancer therapies, in immunology, in neurodegenerative diseases, and as antimicrobials, analyzing pros and cons of this interesting subclass of molecules
- âŚ