376 PATENT ABSTRACTS

cordance with the present invention have uses in is provided. DNA sequence analysis of a clone of vaccine formulations, immunoassays, im- LEU3 shows that it contains an open reading mobilized enzyme reactions, as biological in- frame of 886 amino acids. There are three re- secticides, and as expression vectors, gions of particular interest: a cluster of acidic

amino acids that are located in the C-terminal half of the coding region, a region with a repeated cysteine motif, and a region of partial homology with MATalpha2. A LEU3-

4870026 dependent DNA binding activity is demonstrated to interact with homologous por-

N O N - A , N O N - B . H E P A T I T I S , tions of the 5'-region of LEUI and LEU2. The V I R U S , M E T H O D S O F sequencing of the LEU3 gene, and the identifica-

I D E N T I F I C A T I O N tion of the key sequences within the gene, pro- P U R I F I C A T I O N , vide a means for producing the protein in

C H A R A C T E R I Z A T I O N , deficient yeast strains and non-yeast strains, for modifying the gene in the key regions to thereby

D I A G N O S I S A N D alter DNA binding with LEUI, LEU2, LEU4 I M M U N I Z A T I O N and other genes for proteins and expression of

LEU l, LEU2, LEU4, and LEU3 gene products, Jack Wands, David Shafritz assigned to The and for use within other nucleotide sequences for General Hospital Corporation; The Albert expression in different protein frameworks. In Einstein College of Medicine of Yeshiva one application, synthesis ofleucine, valine, and Universi isoleucine, as well as the expression of the en-

zymes specific to leucine biosynthesis, alpha- A purified form of a DNA virus which has the isopropyl malate synthase, IPM isomerase, and following chvtracteristics: molecular weight beta-IPM dehydrogenase, may be induced or en- greater than 2"106 Daltons; substantial hanced. immunoreactivity towards an anti-HBsAg monoclonal antibody obtained from cell line ATCC HB 8058; substantially no immuno- reactivity towards an anti-HBsAg monoclonal antibody obtained from cell line ATCC CRL 8018; concentration dependent immuno- reactivity towards polyclonal IgG anti-HBsAg antibodies, which increases with increased con- centration of said DNA virus; discrete particu- 4871663 late form when observed by immunoelectron microscopy in the presence of IgM antibodies from cell line ATCC HB 8058; the DNA of said E X P O R E S S I O N V E C T O R F O R virus showing hybridization with DNA from H U M A N T N F hepatitis B viral DNA; and said DNA virus showing, in chimpanzees, infectivity having the Takehiro Oshima, Shoji Tanaka, Shigekazu characteristics of non A, non B hepatitis. Matsukura, Osaka, Japan assigned to Suntory

Limited

The present invention provides a vector plasmid 4870159 capable of efficient tumor necrosis factor (TNF)

production, a process capable of efficient TNF L E U 3 G E N E S E Q U E N C E O F S. production in a host transformed with said plas-

mid and a composition containing the TNF pro- C E R E V I S I A E A N D U S E I N duced by said process. The novel plasmid of the

R E G U L A T I O N O F A M I N O A C I D present invention is characterized by having in- S Y N T H E S I S serted therein a DNA fragment that has a phage-

derived promoter region upstream of a Philip Friden, Paul Schimmel assigned to Mas- structural gene for TNF and in which a DNA sachusetts Institute of Technology fragment containing an E. coli gene-derived

transcription termination coding base sequence An analysis of LEU3, a leucine-specific (terminator) is joined immediately downstream regulatory locus encoding a factor for control of of a base sequence coding for the termination of RNA levels of a group of leucine-specific genes, translation of said structural gene.