The Self-Assembling Peptide P-4 Prevents Collagen Proteolysis in Dentin.

The major goal in restorative dentistry is to develop a true regenerative approach that fully recovers hydroxyapatite crystals within the caries lesion. Recently, a rationally designed self-assembling peptide P-4 (Ace-QQRFEWEFEQQ-NH) has been developed to enhance remineralization on initial caries lesions, yet its applicability on dentin tissues remains unclear. Thus, the present study investigated the interaction of P-4 with the organic dentin components as well as the effect of P-4 on the proteolytic activity, mechanical properties of the bonding interface, and nanoleakage evaluation to artificial caries-affected dentin.

Peptide R18H from BRN2 Transcription Factor POU Domain Displays Antitumor Activity In Vitro and In Vivo and Induces Apoptosis in B16F10-Nex2 Cells.

Background: BRN2 transcription factor is associated with the development of malignant melanoma. The cytotoxic activities and cell death mechanism against B16F10-Nex2 cells were determined with synthetic peptide R18H derived from the POU domain of the BRN2 transcription factor.

Objective: To determine the cell death mechanisms and in vivo activity of peptide R18H derived from the POU domain of the BRN2 transcription factor against B16F10-Nex2 cells.

Covalent binding and anchoring of cytochrome c to mitochondrial mimetic membranes promoted by cholesterol carboxyaldehyde.

Mitochondrial cholesterol has been reported to be increased under specific pathological conditions associated with enhanced oxidative stress parameters. In this scenario, cholesterol oxidation would be increased, leading to the production of reactive aldehydes, including cholesterol carboxyaldehyde (ChAld). By using SDS micelles as a mitochondrial mimetic model, we have demonstrated that ChAld covalently modifies cytochrome c (cytc), a protein known to participate in electron transport and apoptosis signaling.

Towards the mechanisms involved in the antioxidant action of MnIII [meso-tetrakis(4-N-methyl pyridinium) porphyrin] in mitochondria.

Aerobic organisms are afforded with an antioxidant enzymatic apparatus that more recently has been recognized to include cytochrome c, as it is able to prevent hydrogen peroxide generation by returning electrons from the superoxide ion back to the respiratory chain. The present study investigated the glutathione peroxidase (GPx), superoxide dismutase (SOD) and cytochrome c-like antioxidant activities of para Mn(III)TMPyP in isolated rat liver mitochondria (RLM) and mitoplasts. In RLM, Mn(III)TMPyP decreased the lipid-peroxide content associated with glutathione (GSH) depletion consistent with the use of GSH as a reducing agent for high valence states of Mn(III)TMPyP.

Study of respiratory cytochromes in liposomes.

Important findings regarding the structure and function of respiratory cytochromes have been made from the study of these hemeproteins associated to liposomes. These studies contributed to the comprehension of the biological role of these proteins in the electron transfer process, the regulatory mechanisms, the energy transduction mechanisms, the protein sites that interact with mitochondrial membranes and the role played by the non-redox subunits present in the protein complexes of the respiratory chain of eukaryotes. In this chapter, the protocols developed to study cytochrome bc (1) activity in liposomes and the binding of cytochrome c to lipid bilayers is presented .