PATENT ABSTRACTS

4900673

M U T A N T H U M A N A N G I O G E N I N ( A N G I O G E N E S I S F A C T O R W I T H

S U P E R I O R A N G I O G E N I N A C T I V I T Y ) G E N E S T H E R E F O R

A N D M E T H O D S O F E X P R E S S I O N

Jeffrey Harper, Bert L Vallee assigned to Presi- dent and Fellows of Harvard College

Site-specific mutagenesis of a gene for angiogenin producing DNA sequences encoding mutant proteins having increased angiogenic ac- tivity are disclosed. Expression vectors con- taining these sequences are introduced into host cells and direct the production of the mutant angiogenic proteins with markedly increased angiogenic and ribonucleolytic activity. Replacement of a single amino acid, the aspartic acid at position i 16 of human angiogenin, with another amino acid including asparagine, alanine or histidine, yields mutant proteins with 8 to 15 fold increased ribonucleolytic activity toward tR.NA and rRNA and 10 to 100 fold in- creased angiogenic potency in the chorioallan- toic membrane assay. The mutant angiogenin proteins of this invention are useful therapeutic compositions to promote the development of a hemovascular network in a mammal or to pro- mote wound healing, in particular, healing of torn or traumatized fibrocartilage material.

4902620

N O V E L D N A F O R E X P R E S S I O N O F D E L T A - A M I N O L E V U L I N I C

A C I D S Y N T H E T A S E A N D R E L A T E D M E T H O D

4900677

P R O C E S S F O R R A P I D I S O L A T I O N O F H I G H

M O L E C U L A R W E I G H T D N A

Peter L Hewitt assigned to E I Du Pont de Nemours and Company

A procedure for isolating high molecular weight nucleic acids utilizing a mixture of lytic enzymes and a chaotropic agent to complete protein denaturation and dissociation from nucleic acids is provided. The nucleic acids so obtained are useful for restriction enzyme analysis and DNA probe hybridization.

593

Martin Bard, Thomas D Ingolia assigned to Eli Lilly and Company

The present invention is a novel method for maintaining and selecting recombinant DNA- containing host cells wherein the DNA encoding a selectable phenotype and the DNA encoding a useful polypeptide are the same. The af- orementioned DNA is useful for expressing delta-aminolevulinic acid synthetase (ALAS) for the ultimate expression of delta-aminolevulinic acid (ALA) in yeast and related organisms. The invention further comprises plasmids piT300, piT301, piT302, piT304, piT305, piT306 and related Saecharomyces ALA deficient trans- formants. ALA is a five carbon amino acid that is useful as a light dependent herbicide.

4902783

M E T H O D F O R P U R I F Y I N G A G E N E - E X P R E S S I O N P R O D U C T

P R O D U C E D BY R E C O M B I N A N T D N A T E C H N I Q U E

Hideo Goda, Toshiyuki Akiyama, Akihisa Takamizawa, Iwao Yoshida, Takeo Konobe, Keisuke Takaku, Kanonzi, Japan assigned to The Research Foundation for Microbial Dis- eases of Osaka University

There is disclosed a method for purifying a gene- expression product produced by recombinant DNA technique which comprises a specific sequence of steps including adsorption treat- ment with silica gel, adsorption treatment with activated carbon, at least twice density gradient centrifugation and at least twice equilibrium density gradient centrifugation. The method of the present invention is very effective to remove allergen from gene-expression products con- taminated therewith, enabling highly purified gene-expression products to be produced on a large scale.