Site-specific isotopically-labeled proteins, amino acids, and biochemical precursors therefor

摘要

Site-specific isotopically-labelled compounds of formula (Ia) are provided. The amino acids are labelled with 13C or 14C at the methyl group carbon atom(s) most remote from the carboxyl group. Also disclosed are methods for preparing proteins, protein fragments, and polypeptides containing these site-specifically isotopically labelled amino acids.