Nonreaction of Phosphotyrosine with the Folin Phenol Reagent

Bernhard M. K. Gmeiner; Christian. Seelos

doi:10.1021/ac00078a025

DETERMINATION BY THIN-LAYER CHROMATOGRAPHY OF URINARY HOMOVANILLIC ACID IN NORMAL AND DISEASE STATES

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y63-158 ◽

1963 ◽

Vol 41 (1) ◽

pp. 1381-1388 ◽

Cited By ~ 2

Author(s):

Irwin Sankoff ◽

T. L. Sourkes

Keyword(s):

Thin Layer ◽

Thin Layer Chromatography ◽

Homovanillic Acid ◽

Hepatolenticular Degeneration ◽

Huntington's Chorea ◽

Disease States ◽

Acetic Acid Water ◽

Layer Chromatography ◽

Phenol Reagent ◽

Ethyl Acetate Extracts

A rapid method using thin-layer chromatography has been developed to measure urinary HVA (homovanillic acid). Ethyl acetate extracts of urine are chromatographed on glass plates coated with silica gel. The solvent used is the organic phase of benzene: acetic acid: water (2:3:1) mixture. The eluted HVA is treated with Folin's phenol reagent and absorbance is measured at 750 mμ in a spectrophotometer. Normal amounts of HVA in human urine are 8.23 ± 2.96 (mean ± standard deviation) mg/24 hours or 6.42 ± 2.28 mg/g of creatinine. Higher values were obtained in cases of ganglioneuroma and neuroblastoma, in a case of pheochromocytoma, and in one of two cases of hepatolenticular degeneration (Wilson's disease). In three cases of Huntington's chorea, values lay in the normal range.

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THE PARTIAL REACTIVATION OF FORMOLIZED TOBACCO MOSAIC VIRUS PROTEIN

The Journal of General Physiology ◽

10.1085/jgp.22.2.165 ◽

1938 ◽

Vol 22 (2) ◽

pp. 165-191 ◽

Cited By ~ 46

Author(s):

A. Frank Ross ◽

W. M. Stanley

Keyword(s):

Tobacco Mosaic Virus ◽

Mosaic Virus ◽

Amino Nitrogen ◽

Specific Property ◽

Virus Protein ◽

Amino Groups ◽

Reactivation Process ◽

Virus Activity ◽

Simultaneous Decrease ◽

Phenol Reagent

A marked reactivation of tobacco mosaic virus protein that has been partially or completely inactivated by formaldehyde was obtained by dialysis at pH 3. The activity of partially inactivated virus proteins was generally increased about 10-fold by the reactivation process. It was also found possible to reactivate completely inactive preparations to an appreciable extent. It was shown that the inactivation and the subsequent reactivation cannot be explained by the toxicity of the formaldehyde or of the formolized protein or by aggregation. Inactivation was accompanied by a decrease in amino groups as indicated by Van Slyke gasometric determinations and by colorimetric estimations using ninhydrin. Inactivation also causes a decrease in the number of groups that react with Folin's reagent at pH 7.7. The latter are probably the indole nuclei of tryptophane, for it was demonstrated that tryptophane, glycyltryptophane, and indole propionic acid react with formaldehyde in a similar manner, while tyrosine and glycyltyrosine do not. Evidence that reactivation is accompanied by an increase in amino nitrogen and in groups that react with Folin's reagent was obtained by colorimetric estimation. The demonstration that the addition of formaldehyde to the virus protein results in a simultaneous decrease of activity, of amino groups, and of groups that react with Folin's phenol reagent, and that under conditions favorable for the removal of formaldehyde the virus activity is regained and the number of such groups increases, indicates that certain of these groups play at least a partial role in the structure necessary for virus activity. These changes can best be interpreted on the basis of known chemical reactions and are considered as evidence that virus activity is a specific property of the protein.

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Mode of action of the alpha toxin of Staphylococcus aureus

Canadian Journal of Microbiology ◽

10.1139/m70-008 ◽

1970 ◽

Vol 16 (1) ◽

pp. 47-50 ◽

Cited By ~ 6

Author(s):

G. M. Wiseman ◽

J. D. Caird

Keyword(s):

Staphylococcus Aureus ◽

Proteolytic Activity ◽

Mode Of Action ◽

Differential Sensitivity ◽

Aureus Strain ◽

Red Cell ◽

Alpha Toxin ◽

Reaction Products ◽

Phenol Reagent

Rabbit erythrocytes treated with the alpha toxin of Staphylococcus aureus, strain "Wood-46", liberate substances which contain nitrogen, absorb at 280 mμ, and react with Folin phenol reagent. The susceptibility of different erythrocyte species to alpha toxin is correlated with (a) the quantity of reaction products released by toxin from the cells and (b) the degree of natural proteolytic activity possessed by the cells. Alpha toxin was, however, without effect upon albumin, fibrinogen, casein, and hemoglobin even when these proteins had been denatured with urea. In view of the evidence, it is suggested that the toxin is secreted by the Staphylococcus as an inactive protease which must be activated by another protease. The degree of activity of this protease in various red cell species would explain their differential sensitivity to alpha toxin.

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Colorimetric estimation of humic acid with the phenol reagent of folin and ciocalteu

Analytical Biochemistry ◽

10.1016/0003-2697(66)90050-9 ◽

1966 ◽

Vol 14 (1) ◽

pp. 11-16 ◽

Cited By ~ 22

Author(s):

Opendra Kumar Sharma ◽

P.S. Krishnan

Keyword(s):

Humic Acid ◽

Colorimetric Estimation ◽

Phenol Reagent

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A comparative study of the protein content of some helminths and the suitability of assay methods

Journal of Helminthology ◽

10.1017/s0022149x00010452 ◽

1991 ◽

Vol 65 (1) ◽

pp. 62-66

Author(s):

S. M. A. Abidi ◽

W. A. Nizami

Keyword(s):

Comparative Study ◽

Protein Content ◽

Total Protein ◽

Total Protein Content ◽

Brilliant Blue G ◽

Coomassie Brilliant Blue ◽

Tissue Homogenates ◽

Assay Methods ◽

Phenol Reagent ◽

Coomassie Brilliant

ABSTRACTThe protein content of fresh homogenates and their corresponding TCA precipitated fractions of 10 different species of helminths was estimated by the methods of Lowry et al. and Spector using the Folin phenol reagent and Coomassie brilliant blue G-250 respectively. The former method gives exaggerated values as compared to the latter method. The parasite phenols, phenolic proteins and catecholamines could be responsible for interference in the Lowry's procedure. The TCA non-precipitable moieties also give colour only with the Folin phenol assay. The pronounced intra-specific differences in the total protein content of helminths reflect their metabolic variations and adaptations. Habitat does not appear to influence the protein content of parasites, however, the effect of host variation was evident in the pouched amphistome G. crumenifer. It is concluded that the dye binding method gives more consistent results and it can be conveniently applied to crude tissue homogenates of helminths.

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