FOXO4 peptide (Proxofim)

FOX04-DRI (Retro-Inverso) is a synthetic, slightly modified version of the standard FOXO4 protein. The modification prolongs half-life of the protein and allows it to interfere with normal FOXO4 function. FOXO4-DRI has been shown in research to prevent normal FOXO4 binding to p53, thereby allowing for elimination of senescent cells, improved organ function, and younger tissue “biological age.” FOXO4-DRI impacts insulin signaling, cell cycle regulation, and oxidative stress signaling pathways. FOXO4-DRI is a cell penetrating peptide shown to selectively induce apoptosis of senescent cells thereby reversing effects of aging in animal studies.

What Is FOXO4-D-Retro-Inverso (DRI)?

FOXO4 D-Retro-Inverso is identical to the protein product of the FOXO4 gene, but the normal L amino acids have been exchanged for D amino acids. The result is that FOXO4-DRI has reduced susceptibility to normal physiologic clearance mechanisms and thus remains in the body for longer periods of time. The modified protein is still capable, however, of affecting transcription and cellular pathways. In general, the FOXO4-DRI protein interferes with normal FOXO4 function.

Of greatest interest in terms of aging and senescence is the ability of FOXO4-DRI to interfere with normal FOXO4 signaling in the cell cycle by preventing the binding of FOXO4 to p53. The p53 protein is an important regulator of progression through the cell cycle as well as programmed cell death (apoptosis). When FOXO4-DRI binds to p53, it prevents FOXO4 from binding and allows p53 to bind to DNA. This, in turn, allows the cell to continue through the process of apoptosis and die. Interestingly, FOXO4-DRI appears to only have this effect in senescent cells, cells that are no longer functional or are dysfunctional as a result of aging. By targeting these dysfunctional cells, FOXO4-DRI helps to rid tissue of cells that are nothing but dead weight. This, in turn, allows for better tissue functioning and helps to stimulate growth and differentiation of younger, healthier cells. The net result is better biological function and thus a decrease in biological age.

Retro Inverso Peptides Explained

DRI-Retro Inverso Peptides Explained Retro-inverso peptides are linear peptides whose amino acid sequence is reversed and the alpha-center chirality of the amino acid subunits is inverted as well. Usually, these types of peptides are designed by including D-amino acids in the reverse sequence to help maintain side chain topology similar to that of the original L-amino acid peptide and make them more resistant to proteolytic degradation. Other reported synonyms for these peptides in the scientific literature are: Retro-Inverso Peptides, All-D-Retro Peptides, Retro-Enantio Peptides, Retro-Inverso Analogs, Retro-Inverso Analogues, Retro-Inverso Derivatives, and Retro-Inverso Isomers. D-amino acids represent conformational mirror images of natural L-amino acids occurring in natural proteins present in biological systems. Peptides that contain D-amino acids have advantages over peptides that just contain L-amino acids. In general, these types of peptides are less susceptible to proteolytic degradation and have a longer effective time when used as pharmaceuticals. Furthermore, the insertion of D-amino acids in selected sequence regions as sequence blocks containing only D-amino acids or in-between L-amino acids allows the design of peptide-based drugs that are bioactive and possess increased bioavailability in addition to being resistant to proteolysis. Furthermore, if properly designed, retro-inverso peptides can have binding characteristics similar to L-peptides. Retro-inverso peptides are useful candidates for the study of protein-protein interactions by designing peptidomimetics that mimic the shape of peptide epitopes, protein-protein, or protein-peptide interfaces. Retro-inverso-peptides are attractive alternatives to L-peptides used as pharmaceuticals. These of peptide have been reported to elicit lower immunogenic responses compared to L-peptides.

Storage Instructions

All of our products are manufactured using the Lyophilization (Freeze Drying) process, which ensures that our products remain 100% stable for shipping for up to 3-4 months. Once the peptides are reconstituted (mixed with bacteriostatic water), they must be stored in the fridge to maintain stability. After reconstitution, the peptides will remain stable for up to 30 days.

Lyophilization is a unique dehydration process, also known as cryodesiccation, where the peptides are frozen and then subjected to low pressure. This causes the water in the peptide vial to sublimate directly from solid to gas, leaving behind a stable, crystalline white structure known as lyophilized peptide. The puffy white powder can be stored at room temperature until you’re ready to reconstitute it with bacteriostatic water.

Once peptides have been received, it is imperative that they are kept cold and away from light. If the peptides will be used immediately, or in the next several days, weeks or months, short-term refrigeration under 4C (39F) is generally acceptable. Lyophilized peptides are usually stable at room temperatures for several weeks or more, so if they will be utilized within weeks or months such storage is typically adequate. However, for longer term storage (several months to years) it is more preferable to store peptides in a freezer at -80C (-112F). When storing peptides for months or even years, freezing is optimal in order to preserve the peptide’s stability.