Abstract:
Compositions containing therapeutically or immunologically active proteins are rendered substantially free from infectious agents such as viable viruses and bacteria without substantial loss of therapeutic or immunologic activity by mixing the protein composition with a complex formed from source of transition metal ions, such as copper ions, and an angularly-fused, polynuclear heterocyclic arene having two nitrogen atoms in a "cis-ortho" relationship, such as phenanthroline, and a reducing agent such as a thiol in amounts and at a temperature and for a time sufficient to inactivate substantially all of the viruses and bacteria contained therein. Compositions containing therapeutically active proteins substantially free from viral and bacterial infectivity, which have heretofore been unattainable, can be prepared by the method of the invention.
Abstract:
A method for heterologous cloning of a gene encoding alpha -amylase, protease, amyloglucosidase or glucose isomerase. The method involves the use of a bifunctional plasmid which can replicate in both E. coli and B. subtilis, and contains at least two selectable markers. A gene fragment for the enzyme is incorporated into the plasmid, leaving at least one functional selectable marker and a nonfunctional marker, producing a mixture of recombinant hybrid plasmids and the original bifunctional plasmid. This mixture is incorporated into E. coli microorganisms and transformants selected. The transformants which contain the recombinant plasmid are identified, and plasmid DNA extracted. The plasmid DNA is used to transform Bacillus host microorganisms and transformants containing the recombinant plasmids are selected by means of the functional selectable marker.