TABLE 7
FIGURE 16 Spectral titration of soluble factor with half cystinyl P 9 A solution containing 0 16 mg ml of freshly thawed soluble factor bold line is titrated with increasing concentrations of the
FIGURE 10 Differentiation of peroxide and NADPH dependent iodination with thiocyanate Iodination of half cystinyl P 9 catalyzed by thyroidal microsomes is determined as described in METHODS The
TABLE 8
FIGURE 13 Purification of monooxygenases and the unidentified microsomal factor on diethylaminoethyl cellulose Detergent extracts of microsomes are chromatographed as described in text Elution of
nm in reactions catalyzed by thyroid peroxidase 66 Thione forming thiocarbamides are contraindicated in studies potentially involving sulfenyl iodides due to the following reactions 69 Even so these agents are routinely included to determine accumulation of iodide by the thyroid 29 31 39
FIGURE 12 Purification of soluble factor on carboxymethyl cellulose Soluble factor elutes from carboxymethyl cellulose at pH 7 0 Raising the pH of the 10 mM potassium phosphate buffer to 7 7 elutes
Activation parameters Download then all activation parameters Tab 2 will be calculated and the plots according to the ARRHENIUS and EYRING equation will be generated Fig 6 Tab 2 Calculation of the activation parameters
FIGURE 3 Flow chart for resolving and purifying components of the thyroidal iodinating system Centrifugation is represented by speed in thousands of revolutions per minute K rpm All
FIGURE 1 Changes in responses to amines upon exposure to diethylaminoethyl cellulose 99 Preparations of hepatic monooxygenase are assayed with 1 25 mM N N dimethylaniline as previously described
that the thyroid is essential to thermal homeostasis In mammals the synthesis storage and release of hormones from the thyroid is controlled by the following cascade of events 4
Tab 2 Calculation of the activation parameters Fig 6 ARRHENIUS 1 and EYRING plot 2
Enzymes catalyzing the formation of these labile compounds are not known so specificities for various sulfhydryl substrates have not been established In contrast to the reported
FIGURE 18 NADPH dependent iodination of half cystinyl P 9 and lysylglutaryl P 9 with the microsomal and reconstituted systems Iodination of peptides is determined as described in METHODS Filled
TABLE 1
FIGURE 6 Effect of cystamine and dodecylguanidine on the specificity of NADPH dependent iodination Iodination of half cystinyl P 9 catalyzed by thyroidal microsomes is determined as described in
FIGURE 26 Destabilization of intermediary iodines with thyroid peroxidase The system contains 0 6 mg ml of hepatic monooxygenase and 100 µM iodide Destruction of NADPH is monitored as described in
FIGURE 17 Estimation of molecular weights Molecular weights for soluble factor and the hepatic and thyroidal monooxygenases are extimated electrophoretically on polyacrylamide slab gels 103 117
TABLE 5
FIGURE 5 Effect of aging upon NADPH dependent iodination Iodination of N acetyl glutamyl tyrosyl glutamate is determined as described in METHODS except the concentration of iodide in the media is
FIGURE 9 Effect of glutathione on NADPH dependent iodination Iodination of half cystinyl P 9 catalyzed by thyroidal microsomes is determined as described in METHODS with the following changes the
FIGURE 14 Spectra of soluble factor and its deoxy and carbonmonoxy derivatives Spectra of freshly thawed and derivatized soluble factor are obtained with a 0 16 mg ml solution METHODS
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TABLE 4
FIGURE 24 Protection of NADPH by cysteamine in reactions catalyzed by the hepatic monooxygenase Iodide and monooxygenase dependent destruction of NADPH in the presence of the glucose 6 phosphate
with iodinated N hydroxysuccinimidyl 3 4 hydroxyphenyl propionate Bolton Hunter reagent 5 and more recently with N succinimidyl 3 iodobenzoate have therefore been proposed Full View
FIGURE 7 Comparison of peroxide and NADPH dependent iodination Iodination of half cystinyl P 9 catalyzed by thyroidal microsomes is determined as described in METHODS with the following changes
FIGURE 19 Double reciprocal plots of NADPH dependent iodination catalyzed by the reconstituted system Iodination is assayed as described in the legend of Figure 18 Velocities V are expressed in
FIGURE 11 Inhibition of NADPH dependent iodination by thiocyanate NADPH dependent iodination of half cystinyl P 9 catalyzed by thyroidal microsomes is determined as described in the legend of Figure
FIGURE 22 Effect of glutathione on iodide dependent uptake of oxygen catalyzed by the highly purified hepatic monooxygenase Uptake of oxygen is determined as previously described 78 Open circles
FIGURE 4 Subcellular distribution and specificity of thyroidal iodinating activities Subcellular fractions are obtained by differential one hour centrifugations at alkaline pH Iodinating
FIGURE 21 Effect of glutathione and calcium ion on iodide dependent uptake of oxygen catalyzed by the crude hepatic monooxygenase Uptake of oxygen is measured polarographically as previously
FIGURE 2 Effect of pH and 10 mM calcium chloride on the uptake of oxygen catalyzed by hepatic monooxygenase 99 Uptake of oxygen is monitored polarographically 78 with NADPH circles and NADH
37°C The combined action of these enzymes creates a reductive environment in the cytosol by 1 removing peroxide and 2 reducing disulfides RSSR in the following reactions
TABLE 6
FIGURE 15 Spectra of pyridine derivatives of soluble factor Sodium hydroxide 0 02 ml of 6N raises the end point absorbance of a 590 mg ml solution of soluble factor solid line The oxy
FIGURE 23 Effect of calcium ion octylamine and cysteamine on iodide dependent uptake of oxygen catalyzed by crude hepatic monooxygenase Uptake of oxygen is measured polarographically as previously
FIGURE 20 Iodide dependent uptake of oxygen catalyzed by the hepatic monooxygenase Uptake of oxygen is measured polarographically as previously described 78 Double reciprocal plots of velocity
TABLE 3
TABLE 9
Yazeed_Ghawaa: RT @master_usmle: Propythiouracil (PTU): mechanism
It inhibits PTU:
Peroxidase/ Peripheral deiodination
Tyrosine iodination
Union (coupling)
yoosemeli: RT @master_usmle: Propythiouracil (PTU): mechanism
It inhibits PTU:
Peroxidase/ Peripheral deiodination
Tyrosine iodination
Union (coupling)
a4ambitious: RT@master_usmle
Propythiouracil (PTU): mechanism It inhibits PTU: Peroxidase/ Peripheral deiodination Tyrosine iodination Union (coupling)
JaimeGuajardoL: RT @master_usmle: Propythiouracil (PTU): mechanism
It inhibits PTU:
Peroxidase/ Peripheral deiodination
Tyrosine iodination
Union (coupling)
BosunF2: RT @master_usmle: Propythiouracil (PTU): mechanism
It inhibits PTU:
Peroxidase/ Peripheral deiodination
Tyrosine iodination
Union (coupling)
MariTeresa09: RT @master_usmle: Propythiouracil (PTU): mechanism
It inhibits PTU:
Peroxidase/ Peripheral deiodination
Tyrosine iodination
Union (coupling)
master_usmle: Propythiouracil (PTU): mechanism
It inhibits PTU:
Peroxidase/ Peripheral deiodination
Tyrosine iodination
Union (coupling)