Synthesis of a stable isotopically labeled universal surrogate peptide for use as an internal standard in LC‐MS/MS bioanalysis of human IgG and Fc‐fusion protein drug candidates. (4th August 2014)

• Record Type: Journal Article
• Authors: Voronin, Kimberly; Allentoff, Alban J.; Bonacorsi, Samuel J.; Mapelli, Claudio; Gong, Sharon X.; Lee, Ving; Riexinger, Douglas; Sanghvi, Nishith; Jiang, Hao; Zeng, Jianing
• Is Part Of: Journal of labelled compounds & radiopharmaceuticals. Volume 57:Number 9(2014)
• Page Start: 579
• Page End: 583
• Publication Date: 2014-08-04
• Subjects: Tracers (Chemistry) -- Periodicals; Radiopharmaceuticals -- Periodicals; 615.8424
• DOI: 10.1002/jlcr.3218
• Languages: English
• ISSNs: 0362-4803

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The synthesis of a 16‐residue, stable isotopically labeled peptide is described for use as a LC‐MS/MS (Liquid chromatography‐mass spectrometry/mass spectrometry) internal standard in bioanalytical studies. This peptide serves as a single universal surrogate peptide capable of quantifying a wide variety of immunoglobulin G and Fc‐fusion protein drug candidates in animal species used in pre‐clinical drug development studies. An efficient synthesis approach for this peptide was developed using microwave‐assisted solid phase peptide synthesis (SPPS) techniques, which included the use of a pseudoproline dipeptide derivative. The corresponding conventional room temperature SPPS was unsuccessful and gave only mixtures of truncated products. Stable‐labeled leucine was incorporated as a single residue via manual coupling of commercially available Fmoc‐[<sup>13</sup>C<sub>6</sub>, <sup>15</sup>N]‐<sc>l</sc>‐leucine onto an 11‐unit segment followed by automated microwave‐assisted elaboration of the final four residues. Using this approach, the desired labeled peptide was prepared in high purity and in sufficient quantities for long‐term supplies as a bioanalytical internal standard. The results strongly demonstrate the importance of utilizing both microwave‐assisted peptide synthesis and pseudoproline dipeptide techniques to allow the preparation of labeled peptides with highly lipophilic and sterically hindered side‐chains.</p> </abstract>