Fig 6.

Mass spectrum of [¹³C/¹⁵N]arginine obtained from overproduced cyanophycin. Cyanophycin from R. eutropha HF950(pGE779) grown on ¹³CO₂ and ¹⁵NH₄Cl was hydrolyzed, yielding a mixture of SI-labeled arginine (mass, 184.2 Da) and SI-labeled aspartate (not shown), which were chromatographically separated. Mass spectra were measured in positive mode. (This means that the molecular mass is 1 Da higher due to the protonation.) (A) Full spectrum. (B) Zoom into the mass range of 185 Da.