Purification and Characterization of Tyrosinases from Streptomyces albus

Abstract

The bacterium Streptomyces albus has so far never been investigated for tyrosinase activity. The studies presented in this communication show that this bacterium may be a future source for larger production of tyrosinase. The enzyme was purified starting with 5,600 ml of culture filtrate. The crude enzyme was first purified by centrifugation, followed by ammonium sulfate precipitation and ultrafiltration. Then, melanin was removed applying a Servacell DEAE 52 resin, using the batch technique. Thereafter, the crude enzyme was loaded on a SEC Sephacryl S-100 column and, after ultrafiltration, 1.17 mg of purified tyrosinase were obtained. The molecular mass of the purified enzyme was determined by MALDI mass spectrometry to be 30,096 Da which corresponds to the obtained results from SDS-PAGE. Using the diphenol L-DOPA and the monophenol L-tyrosine as substrates, the kinetic parameters for both substrates, Km = 7.8 mM and 0.5 mM and kcat/Km = 157 mM-1 s-1 and 23 mM-1 s-1, respectively, were determined. Maximal activities of the purified enzyme were recorded at pH 7.0. Long-term experiments with Streptomyces albus tyrosinase revealed that storage of the lyophilized enzyme sample at temperatures below zero turned out to be the best. For tyrosinase in buffer containing 20% glycerol, no loss of activity was observed at 4°C and - 60°C

Isolation and characterization of a novel tyrosinase produced by Sahara soil actinobacteria and immobilization on nylon nanofiber membranes

“…The tyrosinase production was reproducible with a production level around 4.6 mg/ml which is higher than that previously observed for S. albus (2.3 mg/ml) (Dolashki et al 2009). Higher production levels of tyrosinase have been reported only when the enzyme is overexpressed in native or in an expression host (Bubacco et al 2000;Guo et al 2015;Ito et al 2000).…”

Partial purification and characterisation of two actinomycete tyrosinases and their application in cross-linking reactions

“…The production levels observed for SPRTyr ( ) [27]. Higher production levels for streptomycete tyrosinases have been reported, but were only achieved when the operon encoding for the tyrosinase was overexpressed either in the native strain (e.g.…”

Isolation and Characterization of Novel Tyrosinase from Laceyella sacchari

“…The protein content of tyrosinase produced from L. sacchari was higher compared to that from S. castaneoglobisporus (12 mg from 1.25 l of culture) [12], from Streptomyces michiganensis (1.7 mg from 2 l of culture) [19] or from Streptomyces albus (1.17 mg from 5.6 l of culture) [20]. However, the overall yield after purification was lower than those for the tyrosinases from S. castaneoglobisporus (15.4 vs. 42%) and T. reesei (15.4 vs. 54% respectively) [12].…”