Pemurnian protease dari daun mengkudu (Morinda citrifolia L.)

Abstract

It has been proved that protease could tenderize meat and octopuses. One of the protease sources is noni (Morinda citrifolias L.) leaves. Yet, the study of proteases in noni leaves has not been reported. The research was aimed to characterize physic and chemistry of noni leaves and purify the protease of noni leaves both from base and shoot part. The physic and chemistry characterization of noni leaves was done by observation and proximate analysis, respectively. The purification of noni leaves proteases was conducted by several steps consisting of extraction, centrifugation, precipitation using saturated ammonium sulfate (100%), dialysis and electrophoresis also zymography. The noni leaves used in this research have facing position, large and thick size, single, flat edge, pinnate veins, green-shiny color, and hairless. Base leaves are dark green dan shoot leaves are light green. The proximate analysis showed that the protein content of base noni leaves (2.92%dry base) was lower than shoot leaves (2.98% dry base). Purification of noni leaves proteases showed that the crude extract of base leaves had higher enzyme specific activity (0.46U/mg protein) than the crude extract of shoot leaves (0.43U/mg protein). Protein content of base leaves (11.29%) was lower than the other (11.47%). Noni leaves purification steps decreased protease specific activity. SDS-PAGE of shoot and base leaves dialysates showed the polypeptides molecular weights were 58- 61.5kDa and 70kDa respectively; whereas zymogram showed the molecular weight of the enzymes are 39kDa and 50kDa.