228 PATENT ABSTRACTS

4707449

PICHIA PASTORIS YEAST STRAINS OF ENHANCED TRYPTOPHAN CONTENT

Lucas K Shay assigned to Phillips Petroleum Company

Mutant Pichia pastoris yeasts which produce relatively high levels of tryptophan. These high tryptophan capability Pichia pastoris mutants, grown on such as methanol or glucose, produce improved amino acid balance single-cell protein product reducing the need to supplement single- cell protein with tryptophan when used as food supplements.

4707542

IMMUNOGENIC HBSAG DERIVED FROM TRANSFORMED

YEAST

Arthur Friedman, E Dale Lehman, William J McAleer, Ted F Schaefer, Edward M Scolnick, D Eugene Wampler assigned to Merck & Co Inc

The surface antigen protein of human Hepatitis B virus is synthesized in Saccharomyces cerevisiae as a 23,000-26,000 dalton polypeptide, essentially free of intermolecular disulfide bonds. This antigen is a poor immunogen in animals and man. No prior precedent or method exists for efficiently converting the non-disulfide bonded antigen to a fully intermolecular dis- ulfide bonded particle. We describe the first ex- ample of such a conversion in vitro and show that the act of this conversion enhances the immunogenicity of the antigen about IO-fold. The in vitro conversion makes practical the pro- duction of hepatitis B surface antigen from microorganisms using recombinant DNA methods.

4708872

ANTITUMOR ANTIBIOTIC COMPLEX

Masataka Konishi, Kyoichiro Saitoh, Hiroaki Ohkuma, Hiroshi Kawaguchi, Kawasaki, Japan assigned to Bristol-Meyers Company

A novel antibiotic complex designated herein as BBM-1675 complex is produced by fermentation

of certain novel strains of Actinomadura ver- rucosospora. The complex may be separated into two major components, BBM-1675 Al and A2, and four minor components, BBM-1675 A3, A4, Bl and B2, and such components exhibit both antimicrobial activity and antitumor ac- tivity.

4708929

METHODS FOR PROTEIN BINDING ENZYME

COMPLEMENTATION ASSAYS

Daniel R Henderson assigned to Microgenics Corporation

This invention relates to improved methods and novel compositions for enzyme complementa- tion assays for qualitative and quantitative determination of a suspected analyte in a sample. The use of enzyme-acceptor and enzyme-donor polypeptides prepared by recombinant DNA techniques or chemical polypeptide synthesis techniques which are capable of interacting to form an active enzyme complex having catalytic activity characteristic of beta-galactosidase is described. Both homogeneous and hetero- geneous assays utilizing these polypeptides are described.

MOLECULAR ANALYTICAL RELEASE TAGS AND THEIR USE

IN CHEMICAL ANALYSIS

Roger W Giese assigned to Northeastern University

A new class of chemical reagents called release tags which comprise signal, release and reactivity groups is disclosed and a release tag involving a pentafluorobenzoyl signal group, a methionylamide release group, and an active ester reactivity group is used to analyze the hor- mone, thyroxine, in serum, involving quantita- tion of the released signal group by gas chromatography with electron capture detec- tion.