Soon-Young Paik

Cloning and Characterization of cDNA Coding for a New Allergen from the House Dust Mite, Dermatophagoides farinae

A cDNA clone encoding a new allergen from the Dermatophagoides farinae cDNA lambda gt11 library was isolated and sequenced. There was no amino acid sequence homology with other known allergens. The gene product, beta-galactosidase fusion protein, of the truncated cDNA on blot reacted with IgE in 13 of 43 sera from patients allergic to mites. The affinity-purified fusion protein had a potent ability to release histamine from washed blood cells of the mite-allergic patients. Human specific IgE eluted from the fusion protein band on blots recognized a 39-kD component on blots of a mite body extract.

Secretory production of ascorbate oxidase by cultured cells of cucumber

Abstract Peelings of cucumber ( Cucumis sativus ) were induced to form callus, which in turn produced ascorbate oxidase, on Murashige-Skoog basal medium with plant hormones. Cell lines which produced high levels of ascorbate oxidase and had a high growth rate were selected. Addition of 100 times more copper, a prosthetic metal of ascorbate oxidase, than that in the basal medium resulted in a significant increase in enzyme activity. A suspension culture of the cells was also established, which was found to produce ascorbate oxidase in the medium. The secretion of the enzyme from the cells was stimulated by addition of calcium ions. Maximum cell yield and maximum levels of ascorbate oxidase were obtained at about the 20th day by shaking culture, but similar growth and enzyme activity were found at the 10th day in an air-lift type jar fermentor.