beta -GALACTOSIDE DOLLAR G(a)-2,6-SIALYLTRANSFERASE

摘要

beta -Galactoside alpha -2,6-sialyltransferase produced by the genetic engineering technique. The enzyme may be deficient in at least a part of the membrane binding region possessed by a naturally occurring beta -galactoside alpha -2,6-sialyltransferase and hence, when expressed in a host, is likely to be secreted outside cells, so that it can be easily prepared and purified. It is prepared by culturing a host cell transformed with an expression vector containing a DNA encoding the amino acid sequence of 16-498 in SEQ ID NO: 1 or DNA encoding a protein which has the same amino acid sequence as the above one, except that one or more amino acids have been deleted, substituted or added, and has a beta -galactoside alpha -2,6-sialyltransferase activity under such conditions as will accelerate the expression of the beta -galactoside alpha -2,6sialyltransferase, and recovering a beta -galactoside alpha -2,6-sialyltransferase protein from the culture.