Biochemical differentiation of clones of OcaOxalis tuberosa,Oxalidaceae) by Their tuber proteins and the properties of these proteins

Tuber proteins of oca (Oxalis tuberosa) were separated for clone (cultivar) differentiation by gel electrophoresis in polyacrylamide. The patterns of native proteins and especially of esterases in a porosity gradient with and without urea were suitable for differentiation, whereas SDS-electrophoresis of protomers or focusing of native proteins yielded more or less the same patterns for 23 different accessions. The main proteins are quite acidic (isoelectric points pH 4.7–4.9) and have a relative molecular weight of 17–18 KD (Kilo-Dalton). Amino acid analysis of the protein precipitate by propan-2-ol from tuber sap revealed proteins rich in aspartic and glutamic acid (one third of all amino acids) with a considerable share of essential ones.