The molluscicidal activities of some Euphorbia milii hybrids against the snail Indoplanorbis exustus.

The objective of this study was to observe the molluscicidal activities of Euphorbia milli, known as "poysean" in Thailand, against Indoplanorbis exustus. Latex from 12 different E. milii hybrids was screened for its molluscicidal activities. Indoplanorbis exustus were exposed for 24 and 48 hours to the latex at various concentrations ranging from 6 to 25 ppm and mortality rates were recorded. Eight hybrids of latex were effective. The six most effective hybrids were E. milii Dang-udom, E. milii Arunroong, E. milii Raweechotchuong, E. milii Srisompote, E. milii Sri-umporn and E. milii Tongnopakun, which killed all snails after 24 hours of exposure. Under the same conditions, latex of E. milii Dowpraket and E. milii Promsatid killed 50% of the snails. Such results indicate that these 6 hybrids seem promising as natural molluscicidal agents.

One-step purification of chimeric green fluorescent protein providing metal-binding avidity and protease recognition sequence.

Gene fusion technique was successfully applied as a potential approach to create a metal-binding site to assist one-step purification of green fluorescent protein (GFP). The chimeric GFP carrying hexapolyhistidine (H6GFPuv) was purified to homogeneous protein via the Immobilized Metal Affinity Chromatography charged with zinc ions. Removal of metal tagger could readily be performed by using enterokinase enzyme. Engineering of the hexahistidine and enterokinase cleavage sites (DDDDK) onto the chimeric protein did not significantly affect the fluorescent property and the binding avidity to Burkholderia pseudomallei protease of a chimeric protease-binding GFP (H6PBGFPuv). This concludes that engineering of repetitive histidine regions onto interested target protein along with the enterokinase cleavage sites will ease the complication of protein purification.