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What Is the Impact of Amino Acid Concentration in the Overall Success of SPPS?

Category: Science Submitted by EmmaWillson 157 day(s) ago (Server time: 23.09.2020 18:58:43)

Solid-phase synthesis is a chemical method used to bound molecules covalently. The process happens on solid materials, while the molecules also get synthesized in a single vessel by using a protective group. This method is useful in the normal synthesis that includes a liquid. 

The whole process is far more straightforward and happens faster. At the same time, there is much better efficiency. By using an excess reagent, this reaction can yield high results. With this method, reactive functional groups protect building blocks.

This way, the order of reactions of functional groups can be controlled with a deprotection order. This is a method used for peptide synthesis, ribonucleic acid, and deoxyribonucleic acid. 

 

What is the solid-phase synthesis of peptides? (SPPS)

This is a popular custom peptide synthesis technique. With regular peptide synthesis, the synthesis comes from a carbonyl group to an amino group. However, with SPPS, the amino acid is always bound to some solid phase material. 

They create a covalent bond, which is usually an ester or an amino bond. The amino group is then deprotected, and it reacts with the carbonyl group of the next protected acid in line. After this, the solid phase has a dipeptide. The whole process is repeated until the desired peptide chain is achieved. 

The most commonly used protecting groups for these amino elements are Butyloxycarbonyl and 9-Fluorenylmethyloxycarbonyl groups. In the side chain, there are many amino acids with functional groups, and they need prevention from reacting with N-protected counterparts. 

 

Why It’s Imperative to Protect Amino Acid Side Chain Hydroxyl Groups in SPPS 

The hydroxyl groups can potentially compete during coupling as nucleophiles. These side chains need to be protected within the amino acids, or else they could lead to impurities, which could damage the overall result. 

It doesn’t always happen, but many potential side reactions can occur and lead to unwanted effects. It also depends on the length of the synthesis. The longer the integration lasts, the higher the chances of something problematic happening, including side reactions. 

Hydroxyl is a very reactive element, and if not protected, it can easily interact with other subsequently added amino acids. 

 

Protecting Amino Acids and Their Side Chains

 

Each amino acid has a carboxylic acid on one and an amino group on the other end. These two groups can attach themselves to each other. N-terminus are the peptides with an amino group, while those with a carboxylic acid are called C-terminus. 

In most cases, peptides synthesis sequences have an N to C flow. But peptides are connected to the C-terminus resin, and this is why they get synthesized in C to N form. To attach each amino acid separately, these groups need to have a Fmoc group, or they would form chains indefinitely. 

But it’s not enough to protect the amino groups only. All of them have side chains with reactive groups. They, too, need to be protected to prevent side effects and reactions. Every custom peptide synthesis needs to have protective groups to ensure these reactions don’t happen. 

 

Summary 

Fmoc SSPS is very efficient and widely used. Still, they have a ton of unfulfilled potential. However, the improvements of various side-chain protection methods and improved building blocks have made custom peptide synthesis results even better.

 

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• biotech

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