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Query: UNIPROT:P15088 (
mast cell
)
14,925
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The O2 binding properties of sulfhemoglobin were studied. The oxygen tension required for half-saturation of sulfhemoglobin is more than 2 orders of magnitude higher than that for hemoglobin A. The binding of O2 exhibits an alkaline Bohr effect larger than that observed for hemoglobin, yet the Hill number is unity. From the Bohr titration curve, 0.68 proton is released during O2 binding at 0 degrees C. Sulfhemoglobin prepared from
carboxypeptidase A
-treated hemoglobin has an affinity for O2 which is about the same as that of sulfhemoglobin at the theoretical limit of the Bohr titration curve. Like its
carboxypeptidase A
-treated hemoglobin precursor, this sulfhemoglobin does not bind O2 cooperatively. Thus, sulfhemoglobin appears to be in a high affinity form at alkaline pH and a low affinity form at acid pH, similar to hemoglobin A. These results demonstrate that the magnitude of the Hill number is not always an indicator of the interaction between oxygen binding and other functions in a hemoglobin.
...
PMID:The reversible binding of oxygen to sulfhemoglobin. 2 95
1. The following proteolytic enzymes were measured in muscles of control subjects and patients with muscular dystrophies and related neuromuscular diseases: an elastase-like enzyme,
carboxypeptidase A
, carboxypeptidase B and pyroglutamyl peptidase. 2. Elastase-like enzyme and carboxypeptidase B did not show significant alterations in various disease conditions that were examined. 3. Carboxypeptidase A was moderately elevated in dystrophic as well as other diseased muscles. 4. Pyroglutamyl peptidase was not markedly altered in any disease condition except that is was slightly lower in dystrophic muscles.
...
PMID:Activity of some proteolytic enzymes in normal and dystrophic human muscle. 3 40
A rapid, inexpensive method for the separation of 5-1-isoleucyl[14C] angiotensin II (A-II) from its various metabolites has been devised. A-II was extracted from tissues with absolute methanol (recovery 96%) and paper chromatographed in a butanol-acetic acid-water (18:2:5) medium for two ascents at 60 degrees C. The resulting RF for A-II of 0.45 was then compared with the RF values of three A-II metabolites produced by enzymatic degradation of the 14C-A-II and [14C]isoleucine. Trypsin degradation produced the [14C]hexapeptide metabolite, chymotryptic degradation produced the [14C]tetrapeptide metabolite and
carboxypeptidase A
degradation produced the [14C]heptapeptide. Increases in temperature produced a continuous increase in RF values for all the substances examined but the resolution decreased above 60 degrees C. Similarly, increases in the temperature caused the appearance of secondary peaks with some but not all peptides. The tryptic digest (hexapeptide) and the chymotryptic digest (tetrapeptide) are apparently acid- and heat-stable under the experimental conditions. All of the peptides examined failed to produce secondary peaks when heated at neutral pH. The method was used to study the tissue distribution of 14C-A-II after intravenous injection.
...
PMID:Rapid paper chromatographic separation of [14C] angiotensen II from some metabolites: application to organ distribution. 3 36
This investigation demonstrates the use of substitution-inert metal ions as site-specific amino acid modifying reagents. The approach involves the production of a chelating agent at the site of interest with the subsequent in situ oxidation of substitution-labile cobalt(II) to exchange-inert cobalt(III) with H2O2. We have produced the chelate complex ethylenediamine-N,N'-diacetato(arsanilazotyrosinato-248
carboxypeptidase A
)cobalt(III) [CoIII(EDDA)(AA-CPA-Zn)]. Model CoIII(EDDA)(azophenolate) complexes have helped to define the reaction conditions necessary to produce the enzyme derivative and have proved invaluable in the spectral analysis of the cobalt(III)-enzyme complex. The modified enzyme contains one active-site zinc and one externally bound cobalt per enzyme monometer. Circular dichroism and visible spectra of the derivative and apoenzyme substantiate the site-specific nature of the incorporation. Concimitant with CoIIIEDDA incorporation, the enzyme loses its peptidase activity yet maintains with FeIIEDTA returns the original properties of the arsanilazotyrosine-248 enzyme.
...
PMID:Development of a method for the incorporation of substitution-inert metal ions into proteins. Site-specific modification of arsanilazotyrosine-248 carboxypeptidase A with cobalt(III). 4 71
Large quantities of the low-molecular-weight natriuretic material (F4), which appears after the salts when fractionated on G-25 Sephadex column, were obtained from the urine of normal man on a normal diet. The natriuretic substance in F4 was (1) untrafiltrable through a membrane with a claimed molecular-weight cut-off of 500 daltons (Amicon UMO5); (2) soluble in more polar organic solvents; (3) totally soluble in 95% acetone when specific activity was doubled; (4) relatively resistant to heating at 100 degrees C for 1 hour at a pH of 10, and to heating at 110 degrees C in 6 N hydrochloric acid for up to 90 hours under anaerobic conditions, and treatment with nitrous acid; it was less resistant to these procedures when extracted into 95% acetone; (5) not destroyed by trypsin, chymotrypsin, pronase, pepsin, leucine aminopeptidase, and subtilysin, nor was it destroyed by pepsin, leucine aminopeptidase, subtilysin,
carboxypeptidase A
and B, and aminopeptidase M, or by monoamine oxidase, aryl sulphatase, and beta-glucuronidase when extracted into 95% acetone. The natriuretic substance in the 95% acetone-soluble F4 was totally destroyed by incubation with prolidase. The least amount of 95% acetone-soluble F4 required to produce a significant natriuresis in the bioassay rat was that derived from a 7-min sample of urine. The maximal response was obtained from a 30-min sample of urine. Continuous i.v. infusion of the 95% acetone-soluble F4 for 40 min produced a sustained natriuresis, whereas a greater amount injected as a bolus produced an effect which was not sustained beyond 20 min.
...
PMID:Further observations on a low-molecular-weight natriuretic substance in the urine of normal man. 4 87
The amino acid sequence of the constant (C) domain of the light chain of the mouse myeloma protein M315 has not been identified so far in any other myeloma protein. In this study, serological analysis with antiserum to the C-domain of this light chain (L315) showed that approximately equal to 1% of Igs in normal mouse serum have L chains of the L315 type (called lambda2). Corroborative evidence was obtained by analysis of the carboxyterminal amino acid removed from normal light chains by
carboxypeptidase A
. A survey of 35 inbred mouse strains showed that all had lambda2; the serum level of Igs with lambda2-chains ranged from approximately equal to 140 microgram/ml in AL/N mice to approximately equal to 25 microgram/ml in SJL, BSVS, and eight other strains. In accord with the anti-Dnp activity of M315, sera from mice immunized with Dnp-KLH had three- to fivefold more lambda2 than sera from control mice immunized with KLH. It was also possible to measure serum immunoglobulin molecules bearing the lambda2 variable region of M315 (VL315). In BALB/c sera, the concentration of VL315 was about sixfold lower than that measured for lambda2. Thus, lambda2-chains are divided into at least two subsets: those whose V domain is indistinguishable from VL315 and those whose VL differs from VL315. A 10-fold increase in VL315 was obtained by immunizing BALB/c mice with Dnp-KLH. The relationship of the VL domains of normal immunoglobulin lambda2-chains to the embryonic Vlambda gene recently sequenced by Tonegawa et al., is discussed.
...
PMID:The natural abundance of lambda2-light chains in inbred mice. 10 27
Cobalt(III)bovine carbonic anhydrase B was prepared by the oxidation of the cobalt(II) enzyme with hydrogen peroxide and was purified by affinity chromatography. The oxidation reaction is inhibited by specific inhibitors of carbonic anhydrase. The inhibition is explained by the fact that the Co(II)-enzyme . inhibitor complex cannot be directly oxidized by hydrogen peroxide, but has to dissociate to give free Co(II) enzyme which is then oxidized. The Co(III) ion in Co(III) carbonic anhydrase cannot be directly substituted by zinc ions. It can be reduced by either dithionite or BH-4 ions to give, first, their complexes with the Co(II) enzyme, and upon their removal, a fully active Co(II) enzyme. Cyanide and azide bind to cobalt(III) carbonic anhydrase with similar rate constants of 0.060 +/- 0.005 and 0.070 +/- 0.007 M-1 S-1 respectively. These rates are faster than those found for Co(III) inorganic complexes. The Co(III) ion in both Co(III) carbonic anhydrase and Co(III)
carboxypeptidase A
was found to be diamagnetic, indicating a near octahedral symmetry.
...
PMID:Kinetic and magnetic properties of cobalt(III) ion in the active site of carbonic anhydrase. 10 27
The Streptomyces aureofaciens extracellular proteolytic system was split into four fractions by carboxymethylcellulose (CMC) column chromatography giving three purely caseinolytic fractions and one fraction active toward both starch and casein. The first caseinolytic and amylolytic fraction was further fractionated by DEAE-Sephadex A-50 chromatography into one purely amylolytic fraction and another showing both activities, was refractioned into four new fractions by DEAE-cellulose chromatography. These fractions were found to be heterogeneous by polyacrylamide gel electrophoresis, three of them acted on both starch and casein and a fourth was only caseinolytic. The second CMC fraction was further purified by CMC rechromatography to an homogeneous fraction that hydrolyzes
carboxypeptidase A
(EC 3.4.2.1) synthetic substrates and solubilizes elastin. It had only one polypeptide chain with a molecular weight of about 28000 daltons, a high thermal stability in the presence of calcium ions, a pH optimum of about 6.8, and a maximal caseinolytic activity at about 50 degrees C.
...
PMID:Fractionation of the proteolytic and amylolytic complex enzyme system of streptomyces aureofaciens and some properties of fractions. 10 83
On the basis of morphological and biochemical differences, the exocrine pancreatic tissue has been divided in peri- and teleinsular regions. In the present study the enzymatic profile of these regions has been investigated by the immunofluorescent technique using antibodies against nine pancreatic enzymes (alpha-amylase, lipase, chymotrypsinogen A, trypsinogen, elastase,
carboxypeptidase A
and B, DNase and RNase A). These antibodies were specific to their antigens without cross reaction. By immunofluorescence, most acinar cells of the normal rat pancreas were positive to the nine enzymes tested. However, an inhomogeneity in the staining pattern was found; specifically, the cells located in the periinsular region of many islets showed a brighter fluorescence than acinar cells in the teleinsular tissue. These data add a new parameter to describe the inhomogeneity of the exocrine pancreas.
...
PMID:Immunohistochemical localization of exocrine enzymes in normal rat pancreas. 11 Aug 72
Rate constants for the interaction of a number of ligands with the active site zinc ion of
carboxypeptidase A
have been measured at pH 7.0, 25 degrees, 1.0 M NaCl. Polydentate ligands such as EDTA, NTA or CyDta do not accelerate the rate at which the zinc ion dissociates from the protein. Bidentate or tridentate ligands on the other hand are able to attack the zinc ion directly; the rates are first order in enzyme and first order in ligand. A mechanism for the reaction is proposed, in which a ternary complex LZnCPA is formed which rapidly dissociates into ZnL and apo CPA. Comparison of results for a variety of ligands leads to the conclusion that in the ternary complex tridentate ligands bind to the zinc ion through only two donor groups. The reaction of 1.10-phenanthroline with ZnCPA has been studied from pH 6 to 9, and a mechanism proposed which accounts for the pH profile of the reaction.
...
PMID:Kinetics of interaction of ligands with carboxypeptidase A. 11 18
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