scholarly journals Proteolytic and peroxidatic reactions of commercial horseradish peroxidase with myelin basic protein

1978 ◽  
Vol 169 (3) ◽  
pp. 567-575 ◽  
Author(s):  
Wendy Cammer ◽  
Lesley Z. Bieler ◽  
William T. Norton
Keyword(s):  
Horseradish Peroxidase ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Protein A ◽  
Low Molecular Weight ◽  
Basic Proteins ◽  
Molecular Weights ◽  
Low Concentrations ◽  
High Concentrations ◽  
A Minor

Degradation of myelin basic protein during incubations with high concentrations of horseradish peroxidase has been demonstrated [Johnson & Cammer (1977) J. Histochem. Cytochem.25, 329–336]. Possible mechanisms for the interaction of the basic protein with peroxidase were investigated in the present study. Because the peroxidase samples previously observed to degrade basic protein were mixtures of isoenzymes, commercial preparations of the separated isoenzymes were tested, and all three degraded basic protein, but to various extents. Three other basic proteins, P2 protein from peripheral nerve myelin, lysozyme and cytochrome c, were not degraded by horseradish peroxidase under the same conditions. Inhibitor studies suggested a minor peroxidatic component in the reaction. Therefore the peroxidatic reaction with basic protein was studied by using low concentrations of peroxidase along with H2O2. Horseradish peroxidase plus H2O2 caused the destruction of basic protein, a reaction inhibited by cyanide, azide, ferrocyanide, tyrosine, di-iodotyrosine and catalase. Lactoperoxidase plus H2O2 and myoglobin plus H2O2 were also effective in destroying the myelin basic protein. Low concentrations of horseradish peroxidase plus H2O2 were not active against other basic proteins, but did destroy casein and fibrinogen. Although high concentrations of peroxidase alone degraded basic protein to low-molecular-weight products, suggesting the operation of a proteolytic enzyme contaminant in the absence of H2O2, incubations with catalytic concentrations of peroxidase in the presence of H2O2 converted basic protein into products with high molecular weights. Our data suggest a mechanism for the latter, peroxidatic, reaction where polymers would form by linking the tyrosine side chains in basic-protein molecules. These data show that the myelin basic protein is unusually susceptible to peroxidatic reactions.

Hydrophobic compounds interfere in radioimmunoassay for basic protein in myelin.

1981 ◽  
Vol 27 (5) ◽  
pp. 742-744 ◽  
Author(s):  
W B Macklin ◽  
M B Lees ◽  
S R Cohen ◽  
S B Ayella
Keyword(s):  
White Matter ◽  
Stearic Acid ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Gm1 Ganglioside ◽  
Hydrophobic Compounds ◽  
Low Concentrations ◽  
High Concentrations ◽  
Protein Assays

Abstract Hydrophobic compounds influenced the accuracy of the radioimmunoassay for myelin basic protein when lipids (stearic acid, phosphatidylcholine, cholesterol, cerebroside, sulfatide, or GM1 ganglioside) or proteolipids (white-matter proteolipid apoprotein, kidney proteolipid apoproteins, or heart proteolipid apoproteins) were added to a known amount of basic protein and the samples assayed. All of these interfere with the assay, but the direction of the error depends on the quantity added: low concentrations of lipid decrease apparent basic protein, high concentrations enhance it. Obviously, results of basic-protein assays must be interpreted carefully.

scholarly journals Interactions of basic polypeptides and proteins with calmodulin

1980 ◽  
Vol 189 (3) ◽  
pp. 455-459 ◽  
Author(s):  
T Itano ◽  
R Itano ◽  
J T Penniston
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Protein Complexes ◽  
Histone H2b ◽  
Basic Proteins ◽  
Inhibitory Compounds ◽  
Low Concentrations ◽  
Synthetic Polypeptides ◽  
Basic Polypeptides ◽  
Stimulation Of

Low concentrations (less than 10 microgram/ml) of a number of highly basic polypeptides inhibit the calmodulin-stimulated cyclic nucleotide phosphodiesterase. Inhibitory compounds include synthetic polypeptides [polylysine (D and L) and polyarginine] and basic proteins (protamine, histones H1, H2A, H2B, H3 and H4 and myelin basic protein). Polylysine of mol.wt. about 2000 or higher was inhibitory, but pentalysine did not inhibit. Other basic proteins and compounds did not inhibit, including bradykinin, spermine and putrescine. In mixtures of calmodulin and basic protein, complexes were formed whether Ca2+ was present or not. This was true for polylysine, myelin basic protein and histone H2B. These interactions suggest that the inhibition of the phosphodiesterase is due to interaction of these basic proteins with calmodulin. The wide variety of basic polypeptides and proteins that affect the calmodulin stimulation of phosphodiesterase indicates that these interactions are not specific.

scholarly journals Colorimetric Analysis with N,N-Dimethyl-p-phenylenediamine of the Uptake of Intravenously Injected Horseradish Peroxidase by Various Tissues of the Rat

1958 ◽  
Vol 4 (5) ◽  
pp. 541-550 ◽  
Author(s):  
Werner Straus
Keyword(s):  
Horseradish Peroxidase ◽  
Blood Serum ◽  
Nerve Tissue ◽  
Colorimetric Determination ◽  
Low Concentrations ◽  
Tissue Homogenates ◽  
Average Activity ◽  
High Concentrations ◽  
Kidney Liver ◽  
Serum And Urine

1. A method is described for the colorimetric determination of peroxidase with N,N-dimethyl-p-phenylenediamine. The amount of red pigment formed by peroxidase is proportional to the concentration of enzyme and to the time of incubation during the first 40 to 90 seconds. The influence of the concentration of enzyme, N,N-dimethyl-p-phenylenediamine, H2O2, the time of incubation, pH, the temperature, and the possible interference by oxidizing and reducing agents of tissues has been tested. 2. The method has been used to follow the uptake of intravenously injected horseradish peroxidase by 18 different tissues of the rat over a period of 30 hours. The highest concentration of the injected tracer enzyme was found in extracts of kidney, liver, bone marrow, thymus, and spleen. Considerable amounts were taken up by pancreas, prostate, epididymis, and small intestine. Lower concentrations were found in extracts of lung, stomach, heart, and skeletal muscle, aorta, skin, and connective tissue. No uptake was observed by brain and peripheral nerve tissue. 3. Tissue homogenates containing high concentrations of the injected peroxidase, in general also showed high or average activity of acid phosphatase. 4. Six hours after intravenous administration, the liver contained 27 per cent, the kidney 12 per cent, and the spleen, 1.4 per cent of the injected dose. 5. Approximately 20 per cent of the injected peroxidase was excreted in the urine during the first 6 hours, and the concentration of peroxidase in blood serum and urine fell exponentially during this time. After 6 hours, only low concentrations were excreted in the urine but low enzyme activity was still detectable after 30 hours. Approximately 6 per cent of the injected dose was excreted in the feces from 6 to 20 hours after administration. 6. After feeding through a stomach tube, low concentrations of peroxidase were found in blood serum and urine. Considerable variations in the extent of absorption from the gastrointestinal tract were observed in individual rats.

Two-dimensional gel electrophoresis of human brain proteins. V. Non-equilibrium gel electrophoresis, with detection of a myelin basic protein mutation--MBL-Duarte.

1982 ◽  
Vol 28 (4) ◽  
pp. 813-818 ◽  
Author(s):  
D E Comings ◽  
A Pekkula-Flagan
Keyword(s):  
Human Brain ◽  
Myelin Basic Protein ◽  
Gel Electrophoresis ◽  
Basic Protein ◽  
Myelin Proteins ◽  
Two Dimensional Gel Electrophoresis ◽  
Brain Proteins ◽  
Basic Proteins ◽  
A Charge ◽  
Non Equilibrium

Abstract To examine the basic human brain proteins, we subjected 9 mmol/L urea extracts to non-equilibrium gel electrophoresis. The pattern observed differs distinctly from that with equilibrium gel electrophoresis. With this technique, the myelin proteins (myelin basic protein, proteolipids, and basic Wolfgram proteins) and many other unindentified major basic proteins can be demonstrated. The myelin basic proteins occur as two major polypeptides of different charge and slightly different molecular mass, indicating the action of at least two genes. The proteolipid proteins occur as a long series of charge isomers, suggesting multiple genes or extensive post-transcriptional modification. In one patient with schizophrenia, a charge-change mutation of the larger myelin basic protein (MBL) was observed and is termed "MBL-Duarte."

The colloidal behaviour of dyes

1952 ◽  
Vol 212 (1109) ◽  
pp. 274-290 ◽  
Keyword(s):  
Molecular Weight ◽  
Orange Ii ◽  
Condensation Polymerization ◽  
Aggregation Process ◽  
Acid Dyes ◽  
Molecular Weights ◽  
Addition Polymerization ◽  
Diffusion Controlled ◽  
Low Concentrations ◽  
High Concentrations

The colloidal behaviour of four acid dyes has been studied by light-scattering. It was shown that none of these dyes was aggregated in the absence of electrolyte and that Orange II does not form stable micelles, even in high concentrations, but the process of flocculation in the absence of dust nuclei can be followed and is similar to addition polymerization. Benzopurpurin forms stable micelles, and the aggregation process is similar to a diffusion-controlled condensation polymerization. In low concentrations of electrolyte, micelles with molecular weights between 10000 and 50000 are formed between 20 and 40° C. In higher concentrations of salt large asymmetric micelles with molecular weights about 10 6 are formed. At 60° C no aggregates were detected in similar electrolyte concentrations. In general, the behaviour of Coomassie Milling Scarlet resembled that of Benzopurpurin except that it was more salt sensitive and did not form giant micelles. Polar Yellow formed a very stable micelle the molecular weight of which, 1·1 x 10 5 , was unchanged over the electrolyte range 0·05 to 0·2 M - NaCl at temperatures between 20 and 60° C, although the micelle dissociates above this temperature. The addition of urea and phenol was found to be effective in preventing the aggregation of Benzopurpurin and Coomassie Milling Scarlet, but not of Polar Yellow. The factors involved in the formation and stability of the colloidal micelles of dyes are discussed.

scholarly journals Immunocytochemical localization studies of myelin basic protein.

1978 ◽  
Vol 76 (2) ◽  
pp. 502-511 ◽  
Author(s):  
J R Mendell ◽  
J N Whitaker
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Horseradish Peroxidase ◽  
Myelin Basic Protein ◽  
Light Microscope ◽  
Basic Protein ◽  
Tissue Fixation ◽  
Immunocytochemical Localization ◽  
Structural Studies ◽  
Immunocytochemical Studies

The location of myelin encephalitogenic or basic protein (BP) in peripheral nervous system (PNS) and central nervous system (CNS) was investigated by immunofluorescence and horseradish peroxidase (HRP) immunocytochemistry. BP or cross-reacting material could be clearly localized to myelin by immunofluorescence and light microscope HRP immunocytochemistry. Fine structural studies proved to be much more difficult, especially in the CNS, due to problems in tissue fixation and penetration of reagents. Sequential fixation in aldehyde followed by ethanol or methanol provided the best conditions for ultrastructural indirect immunocytochemical studies. In PNS tissue, anti-BP was localized exclusively to the intraperiod line of myelin. Because of limitations in technique, the localization of BP in CNS myelin could not be unequivocally determined. In both PNS and CNS tissue, no anti-BP binding to nonmyelin cellular or membranous elements was detected.

HIGH CONCENTRATIONS OF HEPARIN ARE MORE INHIBITORY TO PLATE- AGGREGATION IN-VITRO THAN ARE LOW MOLECULAR WEIGHT HEPARINS AND HEPARINOIDS AT THE SAME CONCENTRATION

1987 ◽  
Author(s):  
H Messmore ◽  
B Griffin ◽  
J Seghatchian ◽  
E Coyne
Keyword(s):  
Molecular Weight ◽  
Heparan Sulfate ◽  
Dermatan Sulfate ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Low Molecular Weight ◽  
Low Concentrations ◽  
High Concentrations ◽  
Induced Aggregation

Other investigators have shown that heparin in the usual therapeutic range (0.1-0.5 units/ml) has an enhancing effect on ADP aggregation and an inhibitory effect on collagen and thrombin induced aggregation. The effects of low molecular weight heparin (LMWH)and heparinoids (dermatan sulfate, heparan sulfate) on platelet aggregation have not been as extensivelystudied. We have utilized citrated platelet rich plasma (3.2%citrate-whole blood 1:9) drawn in plastic and adjusted to a final platelet count of 250,000/ul. A Bio-Data 4 channgl aggregometer was utilized with constantstirring at 37 C. The reaction was allowed to run for 20 minutes. Platelet rich plasma was supplemented 1:9 with saline or heparin and various agonists were then added ifno aggregation occurred. ADP, collagen, thrombin, ristocetin and serum from patients with heparin inudced thrombocytopenia (HIT) were utilized as agonists. Heparin was substituted at concentrations of 0.1 to 500 units per ml and various LMWH and heparinoids were substituted in equivalent anti-Xa or gravimetric concentrations. At low concentrations no inhibitory effect on any ofthe agonists was observed with any of the heparins or heparinoids. At concentrations of heparin of 100 u/ml or greater, all agonists were inhibited. At equivalent concentrations of five different LMWH (Cy 216, Cy 222, Pk 10169, Kabi 2165 and pentasaccharide) inhibition did notoccur at all or at very high concentions only. Dermatan sulfate and heparan sulfate inhibited only at high concentrations. HIT serum could not aggregate platelets with dermatan sulfate or pentasaccharide atany concentrations, but it was a good agonist with the other heparins and heparinoids.

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