Onco-developmentally regulated alpha -N-acetylgalactosaminyltransferase

• Main Authors: MATSUURA; HIDEMITSU, HAKOMORI; SEN-ITIROH
• Format: Patent
• Language: English
• Published: 05.01.1993
• Subjects: BEER; BIOCHEMISTRY; CHEMISTRY; COMPOSITIONS OR TEST PAPERS THEREFOR; COMPOSITIONS THEREOF; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL ORENZYMOLOGICAL PROCESSES; CULTURE MEDIA; ENZYMOLOGY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEICACIDS OR MICROORGANISMS; METALLURGY; MICROBIOLOGY; MICROORGANISMS OR ENZYMES; MUTATION OR GENETIC ENGINEERING; PHYSICS; PROCESSES OF PREPARING SUCH COMPOSITIONS; PROPAGATING, PRESERVING OR MAINTAINING MICROORGANISMS; SPIRITS; TESTING; VINEGAR; WINE

An onco-developmentally regulated alpha -N-acetylgalactosaminyltransferase is isolated as a component of a particulate membrane fraction separated from cell and tissue homogenates which has the following characeristics: (a) Activity in Various Cells and Tissues-present in human fetal lung fibroblasts, hepatoma tissues and placenta, but absent from normal adult liver, lung, kidney and spleen tissues; (b) Substrate Specificity-acts on polypeptides comprising a sequence of val-thr-his-pro-gly-tyr by catalyzing alpha -N-acetylgalactosaminylation at the thr residue of the sequence; (c) Requirements for Metal Ion-requires metal ion for activity in 25 mM tris buffer, pH 7.6; (d) Optimal pH-optimal pH is about 7.6 asssayed in hepatoma cell homogenate in tris buffer and at a pH of about 6 to about 7 assayed in hepatoma cell homogenate enzyme activity is higher in 2(N-morpholino)ethanelsulfonic acid than in cacodylate buffer; and (e) Km-apparent Km for UDP - GalNAc is about 48 mu m. The alpha-N-acetylgalactosaminyltransferase is used in a method of detecting tumor cells. Also, a diagnostic test kit for detecting tumor cells in a sample suspected of containing tumnor cells is disclosed containing as separate components: (a) labeled alpha -N-acetylgalactosamine; and (b) polypeptide substrate comprising a sequence of val-thr-his-pro-gly-tyr.