Purification of a Plant Lectin from Kohlrabi/Brassica oleracea var. gongylodes and Identification of Binding Specificity

Abstract

Plant lectins are proteins that agglutinate cells. They are involved in cancer detection, cell toxicity, and cell growth inhibition. Kohlrabi or Brassica oleracea var. gongylodes is a vegetable that has been associated with a trypsin inhibitor, antifungal peptides, and proteins that have potential anti‐diabetic, anti‐inflammatory, antioxidant properties. A lectin from the same plant species (Brassica oleracea Italica x Alboglabra) was found to have anticancer effects. To our knowledge, we are the first to observe lectin activity from this subspecies known as kohlrabi.. The protein was extracted from kohlrabi cabbage and leaves with Phosphate Buffered Saline (PBS) pH 7.4. Hemagglutination assay was used to detect lectin activity in the crude extraction using 2% (v/v) sheep erythrocytes in PBS. The lectin was purified using size exclusion chromatography Sephadex G‐75. Column fractions were tested for presence of protein by using a UV spectrophotometer at 280 nm and testing for presence of lectin activity using 2% (v/v) sheep erythrocytes. The molecular weight of the lectin was determined using SDS‐PAGE Electrophoresis. Plant lectins bind to specific carbohydrates; the binding specificity of this new plant lectin was identified and in future research the medical application of this lectin can be investigated further.