scholarly journals N-Acetyl-β-d-hexosaminidase component A. Different forms in human tissues and fluids

1973 ◽  
Vol 135 (3) ◽  
pp. 457-462 ◽  
Author(s):  
J. U. Ikonne ◽  
R. B. Ellis

1. Hexosaminidase A of human serum was resolved into two components, a minor form with properties identical with those of the single hexosaminidase A component of human liver, and a major form with significantly different properties. 2. The major serum hexosaminidase A form was eluted from a DEAE-cellulose column at a lower salt concentration than that required to elute the liver form. 3. A multiple-pass technique was used to elute the major serum enzyme A from a Sephadex G-150 column before that of liver enzyme A. 4. Clostridium perfringens neuraminidase converted the major component of serum hexosaminidase A into a form that was held less tightly by DEAE-cellulose, but the minor component of the A enzyme of serum, and the A enzyme of liver were not affected. 5. The hexosaminidase A from tears was similar to the A enzyme from serum, whereas those from several human tissues and from urine and lymph were similar to the liver form. 6. The A enzyme from serum may be derived from the A enzyme from liver by glycosylation before secretion.

1978 ◽  
Vol 173 (1) ◽  
pp. 191-196 ◽  
Author(s):  
M Carroll

Those proteins of human liver that cross-reacted with antibodies raised to apparently homogenous hexosamindases A and B were detected by immunodiffusion. Cross-reacting proteins with high molecular weights (greater than 2000000) and intermediate molecular weights (70000–200000) were present both in the unadsorbed fraction and in the 0.05–0.2M-NaCl eluate obtained by DEAE-cellulose chromatography at pH7.0. The unadsorbed fraction also contained a cross-reacting protein of low molecular weight (10000–70000). The possible structural and functional relationships between hexosaminidase and the cross-reacting proteins are discussed. An apparently cross-reacting protein present in the 0.05M-NaCl eluate from the DEAE-cellulose column was serologically unrelated to hexosaminidase, but it gave a reaction of immunological identify with one of the apparently cross-reacting proteins having the charge and size characteristics of hexosaminidase A. It is suggested that immunochemical methods may provide criteria for the homogeneity of enzyme preparations superior to those of conventional methods.


1979 ◽  
Vol 179 (2) ◽  
pp. 341-352 ◽  
Author(s):  
B W Stewart ◽  
P H Huang ◽  
M J Brian

Rat liver DNA may be separated into two fractions by stepwise elution from benzoylated-DEAE-cellulose with NaCl and caffeine solutions respectively. Other studies using bacterical and yeast DNA suggested that the first fraction contains native DNA, whereas the second may exhibit some degree of single-stranded character. In the present experiments, chromatography of DNA was monitored by labelling in vivo with [methyl-3H]thymidine in rats previously subjected to partial hepatectomy. In animals killed up to 1 h after thymidine injection, radioactivity eluted in the second fraction was inversely related to the incorporation time, being greatest when animals were killed 10 min after radioisotope injection. However, for most experiments, animals were allowed to survive 2-4 weeks after surgery before use, analysis being made on non-dividing DNA. Under these conditions, the proportion of caffeine-eluted DNA was decreased by subjecting the preparation to shear, before chromatography. A procedure that resulted in 12% of the recovered radioactivity being eluted with caffeine was adopted for experiments involving comparisons of the two DNA fractions. Under these conditions, cross-contamination could be detected by rechromatography, but this did not preclude distinction being made between the two fractions in terms of DNA structure. NaCl-eluted DNA did not bind to nitrocellulose filters. Caffeine-eluted DNA was retained by the filters and released by washing with 3mM-Tris/HCl, pH9.4. The fractions did not differ in terms of isopycnic centrifugation in CsCl. The NaCl-eluted fraction migrated as a single band in polyacrylamide gels, and this pattern was not modified by prior digestion with Neurospora crassa endonuclease. In contrast, caffeine-eluted DNA contained a minor component having a wide molecular-weight distribution and was subject to limited digestion by the endonuclease. The kinetics of denaturation of NaCi-eluted DNA in the presence of formaldehyde, in common with unfractionated DNA, were consistent with double-stranded structure. The same analysis of caffeine-eluted DNA revealed structural abnormality equivalent to two defects per 10000 base-pairs. The data are consistent with the minor fraction of rat liver DNA, separated by using benzoylated-DEAE-cellulose, containing regions of local denaturation. We previously showed that administration of the hepatocarcinogen dimethylnitrosamine is associated with an increase in the proportion of caffeine-eluted DNA. In terms of most analysis, differences between DNA fraction from nitrosamine-treated rats were similar to differences exhibited by preparations from control animals. However, structural analysis using denaturation kinetics indicated defects in both the NaCl- and caffeine-eluted DNA isolated from nitrosamine-treated rats. The two fractions differed from each other in that caffeine-eluted DNA exhibited a degree of structural damage far greater than that detected in any preparation from control animals...


1960 ◽  
Vol 13 (1) ◽  
pp. 69 ◽  
Author(s):  
IJ O'donnell ◽  
EOP Thompson

The effect of ionic strength (range 0,15-0, 3), pH (range 7-9), and temperature (range I-25�C) on the chromatographic behaviour of three samples of insulin on diethylaminoethyl (DEAE)-cellulose columns has been studied. These three factors have a similar effect, a decrease of temperature or pH and an increase in ionic strength lowering the elution volume of the protein. The marked effect of temperature is not due to aggregation-disaggregation of the insulin since bovine plasma albumin which does not aggregate reversibly also showed this effect. The desamido component of insulin could not be detected in commercial insulin under the conditions studied but a minor component varying from 2-6 per cent. of the insulin was separated, as well as various amounts of bound ammonia. Removal of zinc from the insulin did not affect the elution curve.


1973 ◽  
Vol 133 (4) ◽  
pp. 641-654 ◽  
Author(s):  
Louis S. Swart ◽  
Thomas Haylett

The complete amino acid sequences of wool protein SCMKB-IIIA3 (131 residues) and a minor component SCMKB-IIIA3A (130 residues) have been determined. The proteins are mutually homologous and have free threonine as the N-terminal residue and carboxymethylcysteine as the C-terminus. The peptides used for the sequence work were obtained by trypsin, thermolysin, pepsin and chymotrypsin digestions and were fractionated by chromatography on DEAE-cellulose, gel filtration on Sephadex G-25 and G-50, paper chromatography and electrophoresis. The Edman degradation method (employing both the Beckman Sequencer and a non-automatic procedure) was used to obtain the sequences of the peptides.


1987 ◽  
Vol 7 (10) ◽  
pp. 813-819 ◽  
Author(s):  
Sabira Naqvi ◽  
Iffat N. Nadvi ◽  
Zafar H. Zaidi

Hemoglobin from the cobra snake, Naja naja naja, was isolated and its chains separated on a CM-cellulose column. The separation profile revealed an α and two β chains having the molar proportions of [α]2,[β1]1,[β2]1. The N-terminal amino acid sequence of the intact chains and of the CNBr peptides were carried out. The β2 chain was found to be heterogeneous comprising a minor component amounting to 11%. This later showed changes at two positions 9 and 14 in the first 30 residues sequenced.


1976 ◽  
Vol 159 (3) ◽  
pp. 535-539 ◽  
Author(s):  
J E S. Lee ◽  
A Yoshida

N-Acetyl-β-hexosaminidases A and B were purified to homogeneity from human placenta. In the initial step of purification, the enzymes were adsorbed on concanavalin A-Sepharose 4B and eluted from the column with α-methyl D-mannosides. Subsequent purification steps included DEAE-cellulose column chromatography, QAE-Sephadex [diethyl-(2-hydroxypropyl)aminoethyl-Sephadex] column chromatography, Sephadex G-200 gel filtration and preparative disc polyacrylamide-gel electrophoresis, followed by another QAE-Sephadex chromatography for the hexosaminidase A preparation, and DEAE-cellulose column chromatography, calcium phosphate gel chromatography, Sephadex G-200 gel filtration, QAE-Sephadex chromatography and CM-cellulose chromatography for the hexosaminidase B preparation. The purified preparations, particularly hexosaminidase A, had significantly higher specific enzyme activities than previously reported. The preparations moved on polyacrylamide-gel electrophoresis as single protein bands, which also stained for enzyme activity. Sedimentation-equilibrium centrifugation indicated homogenous dispersion of the enzymes, and the molecular weight was estimated as about 110000 for both enzymes. Complete amino acid and carbohydrate compositions of the two isoenzymes were determined, and, in contrast with previous suggestions, no sialic acid was found in the enzymes.


1988 ◽  
Vol 252 (2) ◽  
pp. 617-620 ◽  
Author(s):  
T Beccari ◽  
A Orlacchio ◽  
J L Stirling

beta-N-Acetylhexosaminidase from mouse tissue was separated into its constituent isoenzymes on DEAE-cellulose and its activity was monitored with 4-methylumbelliferyl-beta-N-acetylglucosamine and 4-methylumbelliferyl-beta-N-acetylglucosamine 6-sulphate. Forms corresponding to the human isoenzymes A (acidic), B (basic) and an ‘intermediate’ form were present in mouse liver and spleen, whereas in kidney the B and ‘intermediate’ forms predominated, with A present only as a minor component. In brain the ‘intermediate’, A and C activities were detected. Testis had predominantly A activity, whereas epididymis, the tissue with the highest specific activity of beta-N-acetylhexosaminidase, had an abundance of the ‘intermediate’ form, but was almost entirely lacking in the A form.


2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.


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