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A Ullmann

Publications and source records attributed to A Ullmann.

101 records · Page 6Linked to original sources
PubMedDate not supplied

One-step purification of hybrid proteins which have beta-galactosidase activity.

A one-step purification method of hybrid proteins exhibiting beta-galactosidase activity, based on affinity chromatography in the presence of high salt concentration, is described. Starting from crude bacterial extracts, several milligrams of near-homogeneous proteins can be obtained in a few hours with an overall yield of 85 to 95%. The purified hybrid proteins can be used to obtain antibodies against the foreign portion of the protein fusion.

DNA, Recombinant↗
PubMedDate not supplied

An Escherichia coli insertion element (IS2) provides a functional promoter in Bordetella pertussis.

The adenylate cyclase (cyaA) gene of Bordetella pertussis is not expressed in Escherichia coli. Using cya-lac fusions, high-expression spontaneous mutants were isolated and shown to have the insertion element IS2 in orientation II integrated into the reading frame of cyaA. Upon transfer of the IS2-activated cya-lac fusion into B. pertussis, we found that the IS2-provided promoter is as efficient in B. pertussis as it is in E. coli. These results provide evidence that an insertion element derived from the E. coli chromosome can activate gene expression in B. pertussis, a taxonomically distant organism.

Adenylyl Cyclases↗