Total synthesis of fully tritiated leu-enkephalin by enzymatic coupling
✍ Scribed by F. Hellio; G. Lecocq; J. L. Morgat; P. Gueguen
- Book ID
- 102373814
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- French
- Weight
- 392 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0022-2135
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✦ Synopsis
Abstract
This paper describes the total enzymatic synthesis of Leu‐enkephalin (Tyr‐Gly‐Gly‐Phe‐Leu) in which all residues were labelled with tritium. Carboxypeptidase Y from Saccharomyces cerevisiae was the coupling enzyme. [^3^H]‐Tyr‐NH~2~, [^3^H]‐Gly‐Oet, [^3^H]‐Phe‐NH~2~ and [^3^H]‐Leu‐NH~2~ were prepared with specific radioactivities ranging between 20 and 60 Ci/mmol (740 to 2220 GBq/mmol). Using a microscale procedure, we obtained a fully tritiated hormone having a specific radioactivity equal to 139 Ci/mmol (5143 GBq/mmol), in agreement with the summation of the specific radioactivities of constituting residue. The radioactive hormone had antigenic properties identical to those of native Leu‐enkephalin. It also bound to rat brain opiate receptors like the parental hormone.