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      How To Load The First Amino Acid Onto Wang Resin

      Apr 29, 2019 6:05:23 PM / by Elizabeth Denton posted in peptide workflow, solid phase peptide synthesis, first amino acid loading, resin loading, synthesis tips

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      While resins loaded with the natural 20 amino acids are commercially available these days, there may be times when loading the first amino acid onto the resin in house may be necessary.  And unlike loading the first amino acid onto amide-leaving resins, the first coupling reaction for C-terminal acids can be chemically more challenging.

      There are several protocols published both in the literature as well as in technical notes from many peptide reagent and instrument suppliers, but they typically occur at room temperature over extended periods of time (3-24 hours and repeated).  In today’s post, I’ll evaluate several conditions suitable for efficiently loading the first amino acid onto Wang-type resin.

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      How to quantify your first amino acid loading onto Wang resins

      Apr 29, 2019 6:04:33 PM / by Elizabeth Denton posted in solid phase peptide synthesis, quantifying resin loading, first amino acid loading, resin loading, synthesis tips

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      While many of the standard amino acids can be purchased pre-loaded onto Wang type resins, there are still cases where coupling the first amino acid onto Wang resin manually is necessary.  In my case, an unnatural amino acid was required on the C-terminus so there was not a commercially available source.
      This coupling reaction comes with it’s own set of challenges, which is why many people perform a large scale batch preparation of the pre-loaded resin.  But that’s for a later discussion.  In today’s post I’ll address a different question. How do you quantify the amount of amino acid loaded onto the resin?

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