Abstract

Abstract : Light Subunit of Mushroom Tyrosinase (LSMT) is discovered serendipitously during structure elucidation of tyrosinase (PPO3) from the button mushroom Agaricus bisporus. LSMT’s biological function in the mushroom is still unknown. LSMT was known to have homologous to HA-33 from Clostridium botulinum which can facilitates the transport of botulinum toxin across the intestinal epithelial cell monolayer, thereby it has been probed as a drug carrier, and to a ricin-B like lectin from Clitocybe nebularis (CNL) which demonstrates anti-proliferative activity against human leukemic T cells, promoting its use as an anticancer. Based on our previous research, LSMT confirmed its non-toxic and non-immunogenic effect during testing with the animal model, maintains its character to permeate the intestine after modification with captopril, and also displays inhibition of breast cancer cell growth specifically. The aim of this research is to explore the biological activity of LSMT, as compounds that can bind specifically to certain sugar and have specific cytotoxic effect in breast cancer cell lines, and the study of LSMT hemagglutination character on various types of red blood cells was also carried out as the basis for the future development of LSMT as the excipient in the pharmaceutical industry, or could be used in targeted cancer therapy. The binding specificity test between LSMT and simple sugar molecules was done using the Biacore X100 instrument resulting in binding specificity of LSMT only to mannose. This was also confirmed by an in vitro test using MCF-7 cell culture, showing that LSMT specifically toxic, lost its activity when treated simultaneously with mannose solution. In addition, the hemagglutination characteristic test, which was carried out as the basis for future LSMT development as a drug carrier, shows that LSMT up to a concentration of 2000 ppm did not cause agglutination in human’s, mice’s, mouse’s and chicken’s red blood cells. Overall, recombinan LSMT we developed is promising as a drug carrier especially fot breast cancer therapy.