Isolation and characterization of a protease from the Actinidia arguta fruit for improving meat tenderness.

An protease from Actinidia arguta for improving meat tenderness was purified, characterized from wild A. arguta fruit by ammonium sulfate precipitation, Sephdex G-25 gel filtration chromatography, and DEAE Sepharose Fast Flow ion exchange chromatography, and its activity was investigated. The purified protease was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis to obtain a single band of protease. The protease was purified successfully, and found to have a molecular weight of 23.8 kDa (mass spectrometry). The specific activity of the purified protease reached 53,428 U/mg with a 25.5-fold purification factor and 9% activity recovery. Based on N-terminal sequencing results, the A. arguta protease was derived from the class of actinidia proteases that have an N-terminal sequence of VLPDY VDWRS AGAVV. The protease was effective for tenderizing beef and decomposing actomyosin, suggesting the potential application for improving meat tenderness.