The antigens of pigeon breeder's disease. IV. Detection of active enzymes in pigeon dropping extracts.

Two esterase activities were detected in pigeon dropping extracts (PDE). The first exhibited the ability to cleave p-tosyl-L-arginine methyl ester (TAMe), and the second utilized alpha-naphthyl acetate as its substrate. Both enzymes were stable at a temperature of 60 degrees C.

The antigens of pigeon breeder's disease. VII. Isoelectric focusing studies on unfractionated pigeon dropping extract.

Isoelectric focusing (IEF) studies on pigeon dropping extracts (PDE) revealed that it is a complex mixture of components that are acidic in nature. Chromatographically purified antigens PDEB, PDE1, and PDE3 showed multiple bands in IEF, indicating a microheterogeneity of these components, with peak concentrations focusing at pH 6.1, 4.

The antigens of pigeon breeder's disease. III. Immunologically related antigens of pigeon dropping extracts: PDE1,2,A and B.

Antigen PDEB was purified from pigeon dropping extracts and characterized as a basic glycoprotein, containing 93% protein and 7% carbohydrate, with a molecular weight of approximately 51,000. Based on its size, subunit composition, and cross-reactions with PDE1 (pigeon IgA) and papain digestion products of PDE1, PDEB appears to be the basic Fab fragments of antigen PDE1. The acidic Fab fragments (PDEA) and the Fc fragments (PDE2) of PDE1 were also isolated from the whole PDE as 50,000 MW components.

Effect of tryptophan analogs on derepression of the Escherichia coli tryptophan operon by indole-3-propionic acid.

The abilities of 14 tryptophan analogs to repress the tryptophan (trp) operon have been studied in Escherichia coli cells derepressed by incubation with 0.25 mM indole-3-propionic acid (IPA). trp operon expression was monitored by measuring the specific activities of anthranilate synthase (EC 4.