Abstract:To purify and identify stem bromelain for further study on its activity and mechanism after treated with ultrasound.Stem bromelain was purified and identified with carboxymethyl cellulose chromatography and polyacrylamide gel electrophoresis(PAGE) respectively.Enzyme activity,kinetic parameter,ultraviolet spectrum and fluorescence spectrum were studied on purified enzyme treated with ultrasound.Three single protein apex regions were separated with gradient elution.The ingredient with the highest activity in the second protein apex region was identified with PAGE,showing considerably high purity.After treatment with ultrasound,both Km and Vm decreased.No clear changes were observed in the ultraviolet absorption spectrum and the fluorescence emission spectrum while positive and negative peaks occurred in the differential ultraviolet spectrum.Conclusion: Considerably pure component of stem bromelain can be obtained after purified with carboxymethyl cellulose chromatography.It’s probably conformation change that results activity change after treatment of the ultrasound on stem bromelain.
