Integration of Affinity Precipitation with Partitioning Methods for Bioseparation of Chitin Binding Lectins

The present work describes the applications of affinity precipitation and aqueous two-phase affinity extraction (ATPAE) for purification of lectins from wheat germ, potato and tomato. In affinity precipitation, the recoveries of the activities of lectin of 84, 88 and 82% were obtained with concomitant fold purifications of 24, 15 and 16 in cases of wheat germ, potato and tomato, respectively. In ATPAE, 96% of added chitosan partitioned into the PEG phase and enhanced the partitioning of lectins into the PEG phase. The recoveries of the activities of lectin were 90, 85 and 87% from wheat germ, potato and tomato, respectively and the corresponding fold purifications were 25, 37 and 22. Macro-affinity ligand facilitated three-phase partitioning (MLFTPP) is yet another technique which has an inbuilt affinity precipitation step after three-phase partitioning. In this work, MLFTPP has been used in a two-step sequence to separate and purify wheat germ agglutinin and wheat germ lipase (94% activity recovery and 27-fold purification in case of wheat germ agglutinin and 99% activity recovery and 40-fold purification in case of the lipase). All purified preparations showed a single band on SDS-PAGE.