I'm trying to synthesize a polypeptide on Rink Amide resin, and my coupling solution is failing to couple the amino acid onto the deprotected amine group (the resin has been deprotected, confirmed with the Kaiser/ninhydrin Test). I'm using a cocktail of Fmoc-Gln-OH (2eq) in NMP (5 mL/g resin), HATU (2eq of 1.0M in NMP), and DIEA (2eq) in my coupling solution, but it has so far been failing to successfully react with the free amine on the resin. I've allowed the reaction to run for up to two hours (I've tried varying times) but nothing seems to be working. Any suggestions on things I could be doing wrong/how to troubleshoot? I've been having trouble finding literature on coupling solution protocols for SPPS.
Hi everybody. Im a chemistry student and i want to learn about the solid phase in peptide synthesis. Where can i find a protocol?
With that being said, that's about the same start up costs for synthesizing aas raws so there should be plenty of legit sources right? Or is there something I'm missing here?
I have no organizational affiliation. Is it still possible to order custom peptides for personal projects? If yes, how? I have been turned down by a number of companies already.
My lab (US-based, if that matters) is looking to order a short, custom-made peptide (approx. 10 AAs) and I was wondering what companies other labs used.
PEPSTAR, a “rising star” in peptide synthesis, features a “nanostar” support to grow peptides with organic solvent nanofiltration for isolation. The three‐armed and monodisperse nanostar enables efficient nanofiltration and real‐time reaction monitoring. A cycle consists of coupling, Fmoc removal and nanofiltration, which all performed continuously in a synthesizer to produce high purity peptide crudes through a one‐pot approach.
Abstract
Herein, a one‐pot liquid phase peptide synthesis featuring iterative addition of amino acids to a “nanostar” support, with organic solvent nanofiltration (OSN) for isolation of the growing peptide after each synthesis cycle is reported. A cycle consists of coupling, Fmoc removal, then sieving out of the reaction by‐products via nanofiltration in a reactor‐separator, or synthesizer apparatus where no phase or material transfers are required between cycles. The three‐armed and monodisperse nanostar facilitates both efficient nanofiltration and real‐time reaction monitoring of each process cycle. This enabled the synthesis of peptides more efficiently while retaining the full benefits of liquid phase synthesis. PEPSTAR was validated initially with the synthesis of enkephalin‐like model penta‐ and decapeptides, then octreotate amide and finally octreotate. The crude purities compared favorably to vendor produced samples from solid phase synthesis.
https://ift.tt/3nHcrzC
Self‐organization in a system of fatty acids and activated amino acids leads to vesicle‐encapsulated amyloids. The fatty‐acid vesicles act both as a filter, allowing the selective passage of activated amino acids, and as a barrier, blocking the diffusion of the amyloidogenic peptides that form spontaneously inside the vesicles. Hence, a simple mixture of prebiotically plausible starting materials leads to organizationally complex structures.
Abstract
Cellular life requires a high degree of molecular complexity and self‐organization, some of which must have originated in a prebiotic context. Here, we demonstrate how both of these features can emerge in a plausibly prebiotic system. We found that chemical gradients in simple mixtures of activated amino acids and fatty acids can lead to the formation of amyloid‐like peptide fibrils that are localized inside of a proto‐cellular compartment. In this process, the fatty acid or lipid vesicles act both as a filter, allowing the selective passage of activated amino acids, and as a barrier, blocking the diffusion of the amyloidogenic peptides that form spontaneously inside the vesicles. This synergy between two distinct building blocks of life induces a significant increase in molecular complexity and spatial order thereby providing a route for the early molecular evolution that could give rise to a living cell.
https://ift.tt/3oZMmgq
Is it at all times or does it depend on the side chain? Sorry if this is a dumb question lol
Nature Chemistry, Published online: 24 August 2020; doi:10.1038/s41557-020-0525-1
Cyclic β-amino acids can add useful properties to peptides, such as inducing turn structures or providing resistance to proteases. To harness these properties up to ten consecutive cyclic β-amino acids have now been ribosomally incorporated via genetic code reprogramming into a foldamer peptide library that has been screened for potent binders against a protein target, human factor XIIa.
https://ift.tt/3hqYHH1
I'm trying to synthesize a polypeptide on Rink Amide resin, and my coupling solution is failing to couple the amino acid onto the deprotected amine group (the resin has been deprotected, confirmed with the Kaiser/ninhydrin Test). I'm using a cocktail of Fmoc-Gln-OH (2eq) in NMP (5 mL/g resin), HATU (2eq of 1.0M in NMP), and DIEA (2eq) in my coupling solution, but it has so far been failing to successfully react with the free amine on the resin. I've allowed the reaction to run for up to two hours (I've tried varying times) but nothing seems to be working. Any suggestions on things I could be doing wrong/how to troubleshoot? I've been having trouble finding literature on coupling solution protocols for SPPS.
Cellular life requires a high degree of molecular complexity and self‐organization, some of which must have originated in a prebiotic context. Here, we demonstrate how both of these features can emerge in a plausibly prebiotic system. We found that chemical gradients in simple mixtures of activated amino acids and fatty acids can lead to the formation of amyloid‐like peptide fibrils that are localized inside of a proto‐cellular compartment. In this process, the fatty acid or lipid vesicles act both as a filter, allowing the selective passage of activated amino acids, and as a barrier, blocking the diffusion of the amyloidogenic peptides that form spontaneously inside the vesicles. This synergy between two distinct building blocks of life induces a significant increase in molecular complexity and spatial order thereby providing a route for the early molecular evolution that could give rise to a living cell.
https://ift.tt/3oZMmgq
