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Production and purification of mixed 14 C‐labelled peptides derived from plant biomass
Author(s) -
Ling John R.,
Bronwen Cooper P.,
Parker Stephen J.,
Armstead Ian P.
Publication year - 1992
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580310512
Subject(s) - chemistry , chromatography , hordeum vulgare , elution , size exclusion chromatography , amino acid , molecular mass , peptide , trypsin , enzyme , biochemistry , botany , poaceae , biology
Procedures are described for the production and purification of 14 C‐labelled peptides of mixed composition, derived from phytomass. Barley seeds ( Hordeum vulgare ) were germinated and grown in the dark for 6 days. On day 7, the seedlings were exposed to light in a 14 CO 2 atmosphere for 24 h. The plant leaves were harvested and their water‐soluble 14 C‐labelled proteins extracted. These 14 C‐proteins were partially digested by sequential incubation with pepsin, α‐chymotrypsin and trypsin. The resulting 14 C‐labelled peptides were separated from contaminating amino acids by elution from columns of copper‐Chelex resin, and finally fractionated by gel‐filtration chromatography and assigned to groups according to molecular size. The purified 14 C‐peptides ranged in relative molecular mass up to approximately 5,000, possessed a purity in excess of 97%, and were radiolabelled in all amino acid residues with an average specific radioactivity of 450 Bq/μmol. The methods described can be readily adapted to produce not only mixed 14 C‐labelled peptides of any required attribute, such as molecular size or ionic charge, but also mixed 14 C‐proteins of 14 C‐amino acids.