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.

The antigens of pigeon breeder's disease. I. Studies on unfractionated pigeon dropping extracts.

Approximately 6% of the dry organic dust from pigeon coops was extracted in the form of soluble, nondialyzable components. These pigeon dropping extracts contain a number of stable protein and glycoprotein antigens together with pigments and other components that cause nonspecific precipitation of normal and immune sera. Based on their migration in immunoelectrophoresis, the antigens have been designated PDEB, 1, 2, 3 or 4.

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. Although the enzymes could be separated from each other through gel filtration chromatography, both were associated with PDE1 (a major antigen found in pigeon droppings) throughout the fractionation procedure. In addition, it was shown that the TAMe esterase exhibited protease activity by virtue of its ability to hydrolyze alpha-casein.

The antigens of pigeon breeder's disease. II. Isolation and characterization of antigen PDE1.

Antigen PDE1 was purified from pigeon dropping extracts by chromatography on DEAE-cellulose and Bio-Gel A-1.5. It was characterized as a glycoprotein, containing 88% protein and 12% carbohydrate, with a molecular weight of approximately 200,000. PDE1 appears to be derived from pigeon intestinal IgA, showing the typical immunoglobulin structure of heavy and light chains. This antigen represents about 24% of the dry weight of the unfractionated pigeon dropping extract.

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 4.1.3.27) and the tryptophan synthase (EC 4.2.1.20) beta subunit. Analogs characterized by modification or removal of the alpha-amino group or the alpha-carboxyl group did not repress the trp operon. The only analogs among this group that appeared to interact with the trp aporepressor were IPA, which derepressed the trp operon, and d-tryptophan. Analogs with modifications of the indole ring repressed the trp operon to various degrees. 7-Methyl-tryptophan inhibited anthranilate synthase activity and consequently derepressed the trp operon. Additionally, 7-methyltryptophan prevented IPA-mediated derepression but, unlike tryptophan, did so in a non-coordinate manner, with the later enzymes of the operon being relatively more repressed than the early enzymes. The effect of 7-methyltryptophan on IPA-mediated derepression was likely not due to the interaction of IPA with the allosteric site of anthranilate synthase, even though feedback-resistant mutants of anthranilate synthase were partially resistant to derepression by IPA. The effect of 7-methyltryptophan on derepression by IPA was probably due to the effect of the analog-aporepressor complex on trp operon expression.

The isolation and characterization of glutamine-requiring strains of Escherichia coli K12.

Mutants of Escherichia coli K12 requiring glutamine as a nitrogen source were isolated, and characterized as lacking glutamine synthetase activity. Temperature sensitive revertants of one of the mutants had a heat labile glutamine synthetase, while temperature insensitive revertants had a glutamine synthetase which was thermostable in vitro, indicating that the mutation was in the structural gene for the enzyme. All of the mutations mapped in the same region of the chromosome suggesting that they might all be in the same gene. The glutamine synthetase gene (gln) was located on the E. coli chromosome by conjugation and P1-mediated transduction at minute 77. The gln gene cotransduced with the genes for oleate degradation (old), and the genes for L-rhamnose utilization (rha). The most probable gene order is old-gln-rha.

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, 4.6, and 3.8, respectively. The isoelectric points are compatible with the chromatographic behavior of these antigens on DEAE-cellulose. Crossed immunoelectrofocusing (CRIF) resolved PDE into seven precipitin lines with rabbit antiserum in a pH gradient from 3.5 to 9.5, and into nine precipitable components in a pH gradient from 2.5 to 7.0. The complexity of this antigen source appears to reside in the heterogeneity of immunologically related antigens. A comparison of pigeon breeder's sera by CRIF of PDE revealed a qualitative difference in precipitation patterns obtained with symptomatic and asymptomatic individuals. Sera from all (eight out of eight) of the symptomatic breeders tested precipitated an unidentified component of PDE, whereas none (zero out of four) of the sera from asymptomatic breeders detected this antigen. These results suggest that CRIF of PDE is useful as a diagnostic tool and that some specific component of PDE may be involved in the pathogenesis of the disease.