| abstract |
Novel yeast cell transformation vectors are manufactured and employed in securing expression of exogenous polypeptides in yeast cells. Vectors include promoter/regulator DNA sequences of yeast glyceraldehyde-3-phosphate dehydrogenase gene origins. In an illustrative preferred embodiment, novel immunologically active hepatitis B surface antigen (HBsAg) preparations are isolated from yeast cells transformed with plasmid A.T.C.C. 40053. These HBsAg preparations of yeast origin may be incorporated into vaccine compositions useful in developing immunological responses protective against infection by hepatitis B virus. |