Purification and Properties of 4-α-Glucanotransferase Producing Large-Ring Cyclodextrin

Abstract:

4-α-glucanotransferase has the function of generating large-ring cyclodextrin.The crude enzymes production by the genetic mutant of E.coli DH-5α-TA (CGMCC No.3093)was separated and purified by high-temperature processing (65℃,20 min),Ni-NTA affinity column and dialysis.The purified enzyme was demonstrated by SDS-PAGE to be a homogeneous protein and the molecular weight was estimated as 57KDa.It was proved to be with the high level of transglycosylation activity by HPLC which was always used to measure the oligosaccharide and its smallest substrate was maltose.The enzyme exhibited high stability at the temperature range from 70℃ to 85℃ and the pH range from 6.0 to 8.5.The optimal temperature for the enzyme was 75℃ and optimal pH was 7.5,respectively.