摘要 |
<p>A method for determining three-dimensional structural information of a protein involves producing the protein in a form substantially labeled with <13>C or <15>N or both or substantially labeled with <15>N and <13>C and partially labeled with <2>H and subjecting the protein to nuclear magnetic resonance spectroscopic analysis. The isotopically labeled protein is produced by a method which involves producing a substantially labeled microbial protein hydrolysate, subjecting the protein hydrolysate to cation exchange chromatography to produce a partially purified labeled amino acid mixture, subjecting the partially purified labeled amino acid mixture to anion exchange chromatography to produce a purified labeled amino acid mixture and supplementing the purified labeled amino acid mixture with isotopically labeled cysteine and optionally with isotopically labeled glutamine and asparagine.</p> |