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Updated: Aug 12, 2026

Automated System for Single Molecule Fluorescence Measurements of Surface-immobilized Biomolecules
Published on: November 3, 2009
An automated fluorescence protein sequencer using 7-methylthio-4-(2,1,3-benzoxadiazolyl) isothiocyanate (MTBD-NCS) as
Natsuko Okiyama1, Tomofumi Santa, Akira Toriba
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Abstract:
An automated fluorescence protein sequencer using 7-methylthio-5-(2,1,3-benzoxadiazolyl) isithiocyanate (MTBD-NCS), a fluorescent Edman reagent, is developed by the modification of a commercial protein sequencer. The generated MTBD-thiohydantoin amino acids fluoresced strongly, whereas the by-products such as MTBD-thiocarbamoyl amino acids and MTBD-carbamoly amino acids did not fluoresce. A few interfering peaks were observed in the chromatogram and amino acid sequence was easily determined. The coupling and cyclization/cleavage reaction conditions and extraction conditions of generated MTBD-thiazolinone amino acids were optimized using an autonalyzer. Finally, the sequence of a synthetic peptide (25 pmol), leucine-enkephalin-Thr-amide, was determined and up to six residues were successively analyzed.

