Presence Of Indole Research Articles

Phage stabilization I. ability of 19S antibodies to restore T2H adsorption to the bacterial host in the presence of indole

1. 1. Certain strains of bacteriophage are prevented from adsorbing to their bacterial hosts by various factors; strain T2H of the T-even group is prevented from adsorbing to Escherichia coli by indole. 2. 2. In this study it was shown that anti-T2H-sera obtained from chickens early in the course of immunization possess the ability to stabilize the phage in the presence of indole, permitting infection of the host. 3. 3. After purification of the serum globulins from these ‘ early ’ antisera, the phage stabilization properties were shown to reside in the 19S immunoglobulins and were not found to be associated with the 78 immunoglobulins. 4. 4. The mode of action leading to pbage stabilization in the presence of indole was not determined, but it is thought that the antisera interfere with a site on the phage sheath to which the tail fibres bind in the presence of indole. 5. 5. The phage stabilization assay proved to be a sensitive method by which the 19S antibody response in an immune animal could be followed.

Phage stabilization II. the presence of a non-antibody phage-stabilizing factor in normal chicken serum

1. 1. Bacteriophage strain T2H will not infect the bacterial host in the presence of indole; however, phage stabilization (infection) in the presence of indole can be restored by the addition of antiserum containing 19S antibodies to T2H phage. 2. 2. Antiserum to T2H phage exhibits decreased stabilizing properties upon storage or upon beat inacrivation at 56°C. 3. 3. Such antiserum can be restored to normal stabilization levels by the addition of fresh normal chicken serum, which contains a stabilizing factor other than 19S antibodies that reacts with the phage-antibody system to increase stabilizing properties. (Normal chiciren serum does not possess stabilizing properties when added to phage in the absence of antibodies specific to phage.) 4. 4. In addition to being sensitive to storage and heat, the stabilizing factor was found to occur in greater amounts in sera from adult chickens than in sera from young chickens, and was demonstrated to be sensitive to treatment with zymosan. 5. 5. The studies suggest that the complement and/or the properdin systems are involved in the phage-andbody reaction.

The interactions of excited 1,3-Diphenyl-2-pyrazoline with indole and phenol

The fluorescence emission spectrum of 1,3-diphenyl-2-pyrazoline loses its structured appearance and shifts to lower energies in the presence of indole in n-heptane. There is also a decrease in the intensity at the maximum fluorescence position. These changes are similar to those which occur when the diphenyl-pyrazoline is dissolved in solvents of increasing polarity. They are attributed mainly to a high concentration of the indole in the solvent shell of the diphenylpyrazoline and the solvent-shell reorientation processes which result from an increased dipole moment of the diphenyl-pyrazoline in the excited state and which occur in the time interval between absorption and subsequent emission. The NH group is not necessary for the interaction since l,2-dimethylindole brings about similar changes in the fluorescence spectrum of the diphenylpyrazoline. In the presence of phenol the predominant effect is a marked quenching of the fluorescence of the diphenyl-pyrazoline. This is attributed mainly to a hydrogen transfer mechanism operating between phenol and the diphenylpyrazoline.

PRODUCTION OF FREE INDOLE BY SOME AROIDS

SUMMARY The production of free indole by several arum lily species (Araceae) was studied. The compound was identified by paper chromatography and thin-layer chromatography in several solvent systems, colour reactions with various reagents, enzymatic conversion to tryptophan, UV absorption spectrum, and formation of a complex with polynitrofluorenone. The presence of indole is restricted to certain floral parts and is correlated with the flowering sequence of these plants. In general, indole is present for not more than one day during the flowering cycle. In the case of Sauromatum guttatum Schott, production of indole by the appendix starts on the eve of flowering between 6 and 8 p.m. and ends about 24 hours later. At the peak of the metabolic flare-up period, about 0.3 µmoles indole is present per gram fresh tissue. There is a close connection between the indole cycle and the production of heat and stench in the respiratory flare-up. Some of the indole formed is released as a constituent of the stench.

Structural and Functional Roles of the Cysteine Residues in the α Subunit of the Escherichia coli Tryptophan Synthetase

Abstract The reaction pattern of the three sulfhydryl groups of the α subunit of the Escherichia coli tryptophan synthetase with N-ethylmaleimide and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) at pH 7.0 is profoundly altered in the presence of 10 mm indole. The effect of indole is upon both the rate of reaction, and upon its over-all extent. In the absence of indole, only cysteinyl sulfhydryl groups 80 and 117 of the α subunit are available for reaction with N-ethylmaleimide, but in 10 mm indole all three thiol groups become available for reaction. Similar results were obtained with DTNB (i.e. in the absence of indole a single sulfhydryl group reacts rapidly with DTNB, any further reaction occurring very slowly; in the presence of indole all three sulfhydryl groups react at a slower although uniform rate). The effects of indole in the 7.5 to 10.0 mm concentration range could not be mimicked with 20% sucrose, 20% ethanol, 20% ethylene glycol, or 20% dioxane, solvents known to be effective perturbants of protein tertiary structure. The presence of indole also had no effect on the optical rotatory dispersion of the enzyme, and caused no detectable change in the 16 ± 2% α helical structure found for this protein. Indole 3-glycerol phosphate (InGP) at concentrations twice the enzyme's Km for this substrate in the InGP aldolase reaction catalyzed by the free α subunit, protected all three sulfhydryl groups from reaction with DTNB in the presence of indole. Examination of the indole concentration dependence of its effect on sulfhydryl group reactivity, and determination of its Km in the reverse InGP aldolase reaction (synthesis of InGP from indole in the presence of excess d-glyceraldehyde 3-phosphate) showed that the two processes reached half-saturation at indole concentrations of 3.6 and 4.1 mm, respectively. It is concluded that the effect of indole on sulfhydryl group reactivity reflects enzyme conformational changes related to the mechanism of catalysis of the InGP aldolase reaction by the independent α subunit. Indole-induced conformational changes in α subunit structure may be involved in the regulation and catalysis of the last steps in tryptophan synthesis by the α2β2-tryptophan synthetase complex.

?-Chymotrypsin: A Study of the Promotion of the Deacylation Reaction

The effect of indole on the rate of deacylation of acetyl. chymotrypsin has been investigated in detail. In particular, the effects of indole concentration and pH on the magnitude of the increase in the deacylation rate constant have been determined. The deacylation of other acyl�chymotrypsins (formyl., propionyl., and N .formylglycyl.) in the presence of indole has been studied, and benzene, acetamide, and N�acetyltryptamine have been tested as modifiers of the deacylation of formylchymotrypsin. The largest rate enhancement observed was about threefold. Several possible mechanisms for the promotion of the deacylation of acyl�chymotrypsins by hydrophobic compounds are discussed in the light of the results obtained.

Untersuchungen zur Indol-3-essigsäure-Bildung aus Indol,Indol-3-glycerin und Indol-3-glycerinphosphat

Indole or indoleglycerol phosphate were incubated with crude or dialyzed enzyme extracts ( p H 5.4-8.0) of pea seedlings. Neither with nor without addition of serine-like cosubstrates, any formation of auxin or an auxin precursor could be detected by means of the Avena curvature test or thin-layer chromatography. In presence of indole, the auxin content of crude homogenates ( p H 6.8) was slightly enhanced; that was due to an indole-induced inhibition of the breakdown of IAA produced by bacteria during the incubation period. Indoleglycerol was not altered by wheat tissues and was physiologically inactive in the Triticum section test. Wir sind Herrn Dr. F. Lingens für seine Information über die IGP-Synthese und Frl. I. Dörr für ihre gute technische Hilfe zu großem Dank verpflichtet.

The internal low-efficiency promoter of the tryptophan operon of Escherichia coli

Insertional inactivation of the trpE gene in Corynebacterium glutamicum AS019 blocked expression of the trp operon from the primary promoter and resulted in tryptophan auxotrophy. The presence of indole, the substrate for the terminal trp pathway enzyme tryptophan synthase, reversed this auxotrophy thereby providing evidence for the existence of an internal promoter independently expressing the tryptophan synthase genes (trpB and trpA). The toxic tryptophan analogue 6-fluorotryptophan failed to inhibit the growth permitted by indole thus suggesting that expression of tryptophan synthase from the internal promoter is constitutive.

FORMATION AND INTERRELATIONSHIPS OF TRYPTOPHANASE AND TRYPTOPHAN SYNTHETASES IN ESCHERICHIA COLI.

Newton, W. Austin (University of California, Berkeley), and Esmond E. Snell. Formation and interrelationships of tryptophanase and tryptophan synthetases in Escherichia coli. J. Bacteriol. 89:355-364. 1965.-In addition to the classical tryptophan-repressible tryptophan synthetase (TSase-tr), tryptophan auxotrophs of Escherichia coli contain another distinct tryptophan synthetase (TSase-ti) which is induced by tryptophan and is identical with tryptophanase (TPase). Escherichia coli B (wild type) forms only TSase-tr when the growth medium lacks tryptophan. When tryptophan is supplied, parallel induction of TPase and TSase-ti occurs while TSase-tr is repressed. Antiserum prepared against purified TPase neutralized TPase and TSase-ti equally, but not TSase-tr. TPase-negative strains of E. coli do not form TSase-ti. Unlike TSase-tr, TSase-ti is not readily detected by whole-cell assays. In the tryptophan auxotroph, E. coli B/1t7, a direct correlation exists between the effectiveness of 4-, 5-, and 6-methyl-tryptophan in inducing TPase and in promoting growth in the presence of indole. In a mutant of this organism, E. coli B/1t7-A, which is constitutive for TPase, 5-methyl-tryptophan and other substrates of TPase increased the rate of growth on limiting indole, a result ascribed to their ability to inhibit degradation of tryptophan and to supply the 3-carbon side chain for synthesis of tryptophan by TPase. This organism produced maximal amounts of TPase when inocula from log-phase cells grown in tryptophan-supplemented minimal medium were allowed to undergo two cell generations in an enriched broth medium.

Studies on the determination methods with polyaldehydes. II. Colorimetric determination of tryptophan with 5,5'-methylenedi-(2-furaldehyde)

Comparative examinations were made on 2, 5-furandicarboxaldehyde, 5, 5′-methylenedi-(2-furaldehyde), 5, 5′-ethylenedi-(2-furaldehyde), and 5, 5′-oxydimethyldi-(2-furaldehyde) as a coloring agent. 5, 5′-Methylenedi-(2-furaldehyde) reacted with aromatic primary amines to show a characteristic coloration and the colored solution exhibited absorption maximum at 700-750mμ in acetic acid solution. The compound did not react easily with aliphatic amines. Amino acids like glycine, valine, leucine, methionine, cysteine, cystine, glutamic acid, lysine, histidine, proline, tyrosine, and phenylalanine did not undergo coloration with this compound, but tryptophan reacted with it to form a stable reddish violet color with absorption maximum at 510mμ when heated in butanol-acetic acid mixture at 60° for 3 hours. Consequently, the compound can be used for selective coloration of tryptophan in the presence of these amino acids. This coloration is interfered by the presence of indole, 2-methylindole, 3-methylindole, and tryptamine. This method of determination is accurate to within ±3%.

A method for measurement of urinary deoxyribonuclease based on the reaction of indole with deoxyribonucleotides.

SummaryA method is described for measuring urinary deoxyribonuclease activity. The method is based on the reaction of indole in presence of HCl with the products of DNA cleavage. The reaction has been found specific for deoxyribonucleotides and occurs to an insignificant extent with deoxyribonucleosides, free purines or pyrimidines, deoxyribose, and a variety of sugar phosphates other than deoxyribose-5-phosphate.The authors wish to thank Mrs. Leon L. (Elizabeth P.) Miller, Miss Gilda Guarasci, Mrs. Elizabeth Arrowsmith for their technical assistance, Dr. Thomas Koszalka for his advice, and Mr. Donald Gordon for providing us with normal serum.

A FLUOROMETRIC METHOD FOR THE ESTIMATION OF TRYPTOPHAN

The various colorimetric methods now employed for the estimation of tryptophan are not specific for tryptophan but give colored products with many compounds containing the indole nucleus, including indole itself. In order to facilitate studies of the enzymatic synthesis of tryptophan from indole and serine by extracts of Neurospora (1), a search for a rapid, quantitative method for the estimation of tryptophan in the presence of indole was undertaken. Tauber (2) reported that tryptophan gives a green fluorescence when treated with 70 to 72 per cent perchloric acid at room temperature. Modification of this procedure has led to a method for the rapid estimation of tryptophan, without preliminary extraction of indole, in hydrolyzed or unhydrolyzed tryptophan-containing materials.

The Presence of Indole in “Practical” α-Methylnaphthalene

The Presence of Indole in “Practical” α-Methylnaphthalene