The sulphatase of ox liver. XVII. Sulphatase A as a glycoprotein

Extraction and quantification of acrosin, beta-N-acetylglucosaminidase, and arylsulfatase-A from equine ejaculated spermatozoa

Acrosin, Arysulfatase A, and beta-N-acetylglucosaminidase are three key enzymes localized within the mammalian acrosome that play a pivotal role in the penetration of the oocyte. The objectives of this study were to compare two methods of enzyme extraction based on the activities of these enzymes from equine spermatozoa. Method A utilized a 0.5 M Tris-maleate buffer containing 0.1% Triton X-100 and Hyamine 2389. Method B used 0.05 M Tris-HCl, 0.05 M MgCl2 in 0.05 M Tris-maleate, followed by 0.05 M Tris-maleate containing 0.1% Triton X-100. Results indicated that acrosin was initially bound in an acrosin-acrosin inhibitor complex; this complex was dissociated after incubating the extract in 2 mM HCl. Significant (P < 0.001) increases in acrosin activity were found after-acid extraction from 0.076 U/mg after Method B to 0.327 U/mg after Method A. Arylsulfatase A activity was found to have a higher mean activity (P < 0.03) after Method A (0.012 U/mg) as opposed to Method B (0.007 U/mg). Similarly, beta-N-acetylglucosaminidase was found to have a higher mean specific activity (P < 0.001) after Method A (0.037 U/mg) as compared to Method B (0.008 U/mg). This is the first report of the quantification of these enzymes from equine spermatozoa which can ultimately be used as an index of acrosomal damage in cryopreserved semen, and provide additional insight into biochemical alterations between normal vs. abnormal semen.

The isolation and properties of whole casein: some implications for comparative studies

1. Problems in the isolation of whole casein from bovine milk are considered. A summary is given of our experiences in its isolation. 2. The physical characteristics, sedimentation velocity, heterogeneity, absorptivity, nitrogen, phosphorus and carbohydrate contents of whole casein prepared from normal and sub-clinical mastitic milk samples by a variety of methods are compared. The methods are acid precipitation, high-speed centrifugation, with and without added calcium (II), and ammonium sulphate precipitation. 3. A description is given of the low temperature ammonium sulphate procedure preferred for the isolation of whole casein, especially when it is to be used for subsequent fractionation for conformation and micelle studies. 4. The question of the use of bovine casein as a paradigm for the caseins of other mammalian species and the need for further studies of the physical, chemical and biological properties of the caseins are discussed.

Comparison of arylsulphatases from Eimeria tenella (parasite) and chicken caecum (host)

Chicken caecal arylsulphatase was purified 700-fold by (NH4)2SO4 fractionation, concanavalin A-Sepharose and cyclic AMP-Sepharose chromatographies. The purified enzyme was a glycoprotein of Mr 97,000. It hydrolysed p-nitrocatechol sulphate, cerebroside 3-sulphate and ascorbic acid 2-sulphate and was strongly inhibited by Na2SO4 (Ki = 50 microM) and Na3PO4 (Ki = 20 microM). Arylsulphatase from Eimeria tenella sporozoites was purified 28-fold by (NH4)2SO4 fractionation. Arylsulphatase of E. tenella sporozoites was not a glycoprotein. It had an Mr of 49,000. It was inhibited by Na2SO4 (Ki = 300 microM), sodium phosphate (Ki = 90 microM) and heparin. It hydrolysed ascorbic acid 2-sulphate, but cerebroside 3-sulphate was not desulphated. The kinetic parameters of chicken caecal arylsulphatase were different from those of the E. tenella enzyme.

Structural and immunological relationships among mammalian arylsulfatase A enzymes

Structural and immunological properties of numerous arylsulfatase A enzymes (EC 3.1.6) were examined in order to assess the relationships among these enzymes in animals. Arylsulfatase A enzymes from all animals bind to a Concanavalin A-Sepharose column, consistent with the conclusion that they are all glycoproteins. At pH 7.5 the apparent mol. wts of the enzymes are 80-182 kDa, while at pH 4.5 the mammalian arylsulfatase A enzymes dimerize and exhibit apparent mol. wts in the range of 297-348 kDa, but the enzymes from opossum and other lower classes of animals do not aggregate at pH 4.5. The mammalian arylsulfatase A enzymes, which aggregate at pH 4.5, also bind to rabbit liver arylsulfatase A monomers immobilized on an Affi-Gel 10 matrix. The arylsulfatase A enzymes that were studied all exhibit the anomalous kinetic behavior regarded as characteristic of these enzymes. However, not all of the inactivated enzymes are reactivated by sulfate ions. Goat antiserum raised against homogeneous rabbit liver arylsulfatase A cross-reacts with all of the mammalian enzymes in Ouchterlony gel diffusion experiments, whereas the enzymes from lower classes of animals do not cross-react. Quantitative immunoprecipitation experiments demonstrate that the mammalian enzymes are very similar to each other, with greater than 60% primary sequence homology indicated, while arylsulfatase A from opossum and other lower classes of animals show only a partial immunological similarity with the mammalian enzymes. Taken together, the data suggest that the active site of the enzyme and the structural features of the protein are highly conserved during the evolution of the enzyme molecule.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and characterization of the pig endometrial arylsulphatase A

The pig endometrial arylsulphatase A was purified 3322-fold to a specific activity of 150 mumol/min per mg. The purification involved (NH4)2SO4 fractionation, chromatography on concanavalin A-Sepharose and DEAE-Sepharose, gel filtrations on Sephadex G-200 at pH 7.4 and 5, and a new preparative gel-electrophoresis technique. The homogeneous enzyme is a glycoprotein containing 20% carbohydrate. The purified enzyme has Mr about 120 000 and it contains subunits of Mr 63 000. The pig endometrial arylsulphatase A shows many properties in common with those of arylsulphatases A purified from other sources. The similarities include their low isoelectric points, the anomalous time-activity relationships, multi-pH optima, inhibition by SO3(2-), SO4(2-), phosphate ions, metal ions and nucleoside phosphates, pH- and ionic-strength-dependent polymerization and amino acid composition.

Arylsulfatases of human-lung tumors transplanted into athymic mice. Cancer-associated modification of arylsulfatase B variant

The activities and properties of arylsulfatase A and B from human lung carcinoma transplanted into athymic mice were demonstrated. The activities of arylsulfatase A and B from transplanted carcinomas with four histological types were more than twofold higher as compared to those from surgical tumors, except for arylsulfatase A activity in blastoma. Arylsulfatase B in transplanted tumors was almost completely replaced, except for blastoma, by an anionic B variant (B1) which was a minor component of arylsulfatase B in surgical lung tumor and absent in normal human lung. The properties of arylsulfatases A and B from transplanted tumors were essentially identical, respectively, with those from normal lung or surgical tumors in respect of molecular weight, heat stability, pH optimum, isoelectric point (pI), Km, time course profile and substrate specificity. Arylsulfatase B1 showed the properties similar to B enzyme except for net charge. The cause of the negative charge of tumor B1 enzyme was investigated. By the action of phosphatase, which was added exogenously or had been persistently included in the partially purified enzyme preparation, B1 enzyme (pI 7.5) shifted to about pI 8.2. Treatment of B1 enzyme with neuraminidase, concomitant with the endogenous phosphatase, resulted in marked increase (pI 9.5) of the isoelectric point, identical to that of arylsulfatase B. Thus, it is most probable that tumor B1 enzyme is modified by additional sialic acid and phosphate bound to arylsulfate B.

Comparison of dipeptidyl peptidase IV prepared from pig liver and kidney

Dipeptidyl peptidase IV (dipeptidylpeptide hydrolase, EC 3.4.14.-) has been purified from the microsomal fraction of pig liver, using an immunoaffinity chromatography, and its properties compared with those of the enzyme purified from pig kidney. The amino acid compositions of both enzymes were similar. The same kinds of carbohydrates were found in both enzymes, but there were differences in the molar concentrations of individual sugars. The liver enzyme had greater concentrations of mannose, fucose and sialic acid than the kidney enzyme, while the concentrations of galactose and glucosamine were greater in the kidney enzyme. The carbohydrates accounted for approx. 18.3 and 22.7% of the weight of the kidney and liver enzymes, respectively. The pH optima, molecular weights, substrate specificities and Km values of the two enzymes and the effects of diisopropylfluorophosphate on their activities were nearly identical. The liver enzyme was heat- and pH-sensitive, but not attacked by proteinases.

A variant form of arylsulfatase A in human urine derived directly from the renal pelvis: kinetic and immunological characterization

Arylsulfatase A (aryl-sulfate sulfohydrolase, EC 3.1.6.1) was examined in voided and in nephrostomic urine. A variant form of the enzyme was found in nephrostomic urine, in addition to the minor form, which is the sole component of arylsulfatase A in voided urine. The nephrostomic enzyme differed from the voided urine enzyme with respect to the kinetic parameters, the isoelectric point, heat stability and immunological reactivity. The isoelectric points of the voided urine and nephrostomic enzymes were 4.7 and 5.3, respectively. The nephrostomic enzyme was more heat-labile at 62.5 degrees C than the voided urine enzyme. Although the Km values of the two enzymes with nitrocatechol sulfate as substrate were almost the same, the V value of the nephrostomic enzyme was approx. one-hundredth that of the voided urine enzyme. The molecular weight (almost 130 000) did not differ between the voided urine and nephrostomic enzymes. It was demonstrated by various methods, using IgG antibody against the purified voided urine enzyme, that the nephrostomic enzyme was antigenically distinct from the voided urine enzyme.

Chemical characterization and substrate specificity of rabbit liver aryl sulfatase A

Rabbit liver aryl sulfatase A (aryl-sulfate sulfohydrolase, EC 3.1.6.1) is a glycoprotein containing 4.6% carbohydrate in the form of 25 residues of mannose, seven residues of N-acetylglucosamine, and three residues of sialic acid per enzyme monomer of molecular weight 140 000. Each monomer consists of two equivalent polypeptide chains. The protein has a relatively high content of proline, glycine and leucine, and the amino acid composition of rabbit liver aryl sulfatase A is similar to that of other known liver sulfatases. Rabbit liver aryl sulfatase A catalyzes the hydrolysis of a wide variety of sulfate esters, although it appears possible that cerebroside sulfate is a physiological substrate for the enzyme because the Km is very low (0.06 mM). The turnover rate for hydrolysis of nitrocatechol sulfate or related synthetic substrates is much higher than the rate with most naturally occurring sulfate esters such as cereroside sulfate, steroid sulfates, L-tyrosine sulfate or glucose 6-sulfate. However, the turnover rate with ascorbate 2-sulfate is comparable to the rates measured using most synthetic substrates. These results are discussed in relationship to several previously described sulfatase enzymes which were claimed to have unique specificities.

Enzymes of the mast cell granule

Rat mast cell granules contain a spectrum of enzymes as established by histochemical techniques and subcellular fractionation. However, 35% of the beta-glucuronidase, 30% of the beta-D-galactosidase, 14% of the beta-hexosaminidase and all of the acid phosphatase is not available for immunologic release from purified rat serosal mast cells, suggesting the presence of nonsecretory lysosomes containing these acid hydrolases. On the other hand, immunologic release of the majority of chymase, beta-hexosaminidase, beta-glucuronidase, beta-D-galactosidase, and arylsulfatase A occurs in parallel with histamine and thereby localizes these substances to the rat mast cell secretory granule. A molecular model of the secretory granule in the resting mast cell can now be constructed in which heparin proteoglycan is the granule matrix to which chymase and probably other proteins are ionically bound. Inhibition of chymase by serotonin stored in its active site and of chymase and acid hydrolases by their interaction with heparin probably occurs. Histamine is stored by ionic linkage to carboxyl groups of protein and heparin. Micromolar amounts of heparin glycosaminoglycans, histamine, serotonin, chymase, beta-D-hexosaminidase, beta-glucuronidase, and arylsulfatase A in secretory granules of 10(6) mast cells are 0.7--1.3 x 10(-3), 70--220 x 10(-3), 0.9--28 x 10(-3), 0.2--0.5 x 10(-3), 0.9--2.7 x 10(-6), 0.1--0.3 x 10(-6) and less than 8 x 10(-6), respectively. In addition, the total protein available for calcium ionophore-induced release from 10(6) rat mast cells is about 60 microgram, indicating that less than 50% of the granule protein can be accounted for. Recognition that mast cell secretory granules contain acid hydrolases indicates that they are modified lysosomes; their special intracellular and extracellular functions are dictated by the associated novel constituents and the stimulus for activation.

Purification and some properties of tartrate-sensitive acid phosphatase from rabbit kidney cortex

Two forms of tartrate-sensitive acid phosphatases (EC 3.1.3.2) were purified from rabbit kidney cortex by a multiple-column-chromatography method. The basic form constituted 90% of the enzyme and migrated as a single band of protein on polyacrylamide-gel electrophoresis. The proteins contaminating the acidic form did not exceed 5% of the total protein. The specific activity towards p-nitrophenyl phosphate was 12 mumol/min per mg for the basic form and 0.7 mumol/min per mg for the acidic form. The basic form of the enzyme differs from the acidic form in its heat-stability, Km values, inhibition rates by tartrate and fluoride and substrate specificities. Relative to p-nitrophenyl phosphate hydrolysis rate, the acidic form hydrolysed a variety of physiological monophosphate esters, whereas the basic form hydrolysed only CMP and phosphoenolpyruvate. Bacterial neuraminidases had no effect on the activity and mobility of the acidic form on polyacrylamide-gel electrophoresis. Both forms have the same molecular weight (101000 +/- 4000) and are probably composed of two identical subunits. The question whether the two forms of the enzyme are different proteins or whether one is a modified form of the other is discussed.

The sulphatase of ox liver. XX. The preparation of sulphatases B1alpha and B1beta

Sulphatases B1alpha and B1beta (EC 3.1.6.1) have been prepared as apparently homogeneous proteins by chromatography on ConA-Sepharose. Both have a mol. wt. of 56 000, and E1%280nm of 17 and a turnover number of 8600 min-1 with nitrocatechol sulphate as substrate. Their amino acid compositions are identical: like sulphatase A, the sulphatases B are rich in proline and yield glucosamine on hydrolysis. They are not altered by treatment with neuraminidase. Both fractions show strong UDP-N-acetylgalactosamine 4-sulphatase activity, weak iduronate sulphatase activity, but no significant heparan N-sulphatase activity. It is suggested that the physiological activity of sulphatase B is that of the N-acetylgalactosamine 4-sulphatase which is lacking in the Maroteaux-Lamy Syndrome.

Arylsulphatase a and 2',3'-cyclic nucleotide 3'-phosphohydrolase activities in the brains of myelin deficient mutant mice

Arylsulphatase A and 2',3'-cyclic nucleotide 3'-phosphohydrolase activities of myelin deficient mutant mice brains were studied. The results indicated that there were no changes in arylsulphatase A activity of the developing mutant brain, whereas the activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase decreased considerably. The data obtained in this study suggest that in brain arylsulphatase A activity is localized in cells other than oligodendroglia.

Purification and properties of arylsulphatase from the brain of the silkworm Bombyx mori

(1) Arylsulphatase of the silkworm Bombyx mori was partially purified using ammonium sulphate fractionation, ethanol precipitation, Sephadex G-200 gel filtration and Con-A Sepharose chromatography. (2) The purified enzyme preparation was not homogeneous but showed no beta-glucuronidase or beta-galactosidase activities. (3) The kinetic properties of the enzyme indicated that it could be classified under type-2 arylsulphatases of vertebrates. (4) The purified enzyme shows very little activity towards p-nitrophenyl sulphate and none towards cerebroside 3-sulphate.

The sulphatase of ox liver. XIX. On the nature of the polymeric forms of sulphatase A present in dilute solutions

Weight-average elution volumes of sulphatase A (an arylsulphate sulphohydrolase, EC 3.1.6.1) from Sephadex G-200 have been determined as functions of protein concentration, pH, ionic strength and temperature. The results are used to calculate the apparent association equilibrium constants for tetramer formation and the associated standard-state thermodynamic parameters. While the apparent association constant decreased from 10(28) to 10(21) M-3 on increasing the pH from 4.5 to 5.6 at ionic strength 0.1, at any particular pH value studied it was relatively insensitive to temperature variation so that deltaH is close to zero and tetramer formation in solution is associated with a positive entropy change. At pH 5.0, increasing the ionic strength from 0.1 to 2 decreased the association constant by a factor of 100. Methylumbelliferone sulphate has no effect on the association of sulphatase A. The equilibrium results are used to define the degree of association of sulphatase A likely to encountered in experiments designed to elucidate its kinetic properties. In the liver lysosome, the tetramer is probably the dominant species. The monomer and tetramer of sulphatase A have similar, or identical, specific activities with nitrocatechol sulphate and 4-methylumbelliferone sulphate as substrates. With nitrocatechol sulphate, sulphatase A shows Michaelis kinetics under conditions where the monomer is the dominant species and non-Michaelis kinetics where the tetramer is dominant. There is apparently a negative cooperativity between the monomer units in the tetramer. In 2 mM sodium taurodeoxycholate and 0.035 M MnCl2, but not in 0.1 M NaCl, the tetramer shows Michaelis kinetics. This is not due to dissociation of the tetramer. The critical micellar concentration of sodium taurodeoxycholate is about 0.8 mM in both 0.1 M NaCl and 0.035 M McCl2 but the aggregation number is greater in the latter.

Enzymes from human articular cartilage: isolation of arylsulfatase B and its comparison with arylsulfatase A

This study describes the isolation of arylsulfatases A and B (arylsulfate sulfohydrolase EC 3.1.6.1) from human articular cartilage. These enzymes were extracted from collagenase digests of tissue homogenates. After fractionation with ammonium sulfate the enzymes were separated from each other by DEAE-cellulose chromatography and further purified by gel filtration on Sephadex G-200. Sulfatase B, subsequently chromatographed on CM-cellulose was apparently homogenous as judged by polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate. The enzyme has a pH optimum of 5.6, a molecular weight of 51,000 and Km of 2.6 mM for 4-nitrocatechol sulfate. Sulfatase A was found to be a glycoprotein with a pH optimum of 4.8, a molecular weight of 105,000 and a Km of 0.16 mM for 4-nitrocatechol sulfate. The competitive inhibition of both enzymes by inorganic sulfate, sulfite and phosphate support the likelihood of a common reaction mechanism. In contrast to sulfatase B which showed minimal inhibition, sulfatase A was totally inhibited by 5 mM N-ethylmaleimide.

Purification and properties of human placenta arylsulphatase A

1. Arylsulphatase A (arylsulphate sulphohydrolase E.N. 3.1.6.1) has been purified 7200-fold from human placenta using concanavalin A Sepharose chromatography. 2. Ultracentrifugation studies indicated that the purified enzyme was homogenous with respect to sedimentation coefficient and molecular weight and has a molecular weight of 102000. 3. The purified enzyme could hydrolyze cerebroside 3-sulphate, seminolipid and sulphogalactosylsphingosine under identical conditions. 4. The kinetic parameters for the hydrolysis of all sulphate esters used in the present study were the same. 5. Both seminolipid and sulphogalactosylsphingosine were competitive inhibitors for the hydrolysis of cerebroside-3-sulphate with an inhibition constant of 0.2 mM. 6. Kinetic parameters, metal ion effect and heat inactivation profile of enzyme suggest that the same active site of enzyme is responsible for the hydrolysis of cerebroside 3-sulphate, seminolipid and sulphogalactosylsphingosine.

Purification, properties and glycoprotein nature of arylsulfatase A from sheep brain

A simple and rapid method for the purification of arylsulfatase A (EC 3.1.6.1) from sheep brain has been developed. This includes the concanavalin A-Sepharose affinity chromatography and the pH-dependent polymerization and depolymerization of the enzyme. By these methods a homogeneous enzyme was obtained and the enzyme was purified 7180-fold. Sheep brain arylsulfatase A has been shown to be a glycoprotein containing 25% neutral sugar and 0.5% sialic acid. The constituent neutral sugars were identified as glucose and mannose.

Anesthesia and the golgi apparatus: enzyme activity changes in a golgi-rich fraction of rat liver after a short ether anesthesia

Activity changes of enzymes in isolated rat liver Golgi preparations at different times (1-48 h) after a short ether anesthesia are reported. Activity of galactosyl-transferase showed a slight gradual increase but thiamine pyrophosphatase decreased sharply, and after 24 h increased to above control level. Arylsulphatase-A remained largely unchanged, and B was significantly decreased. Acid phosphatase activity did remain at the control level, but alkali phosphatase showed a gradual and highly significant increase. Five other enzymes representing probable contaminations from other subcellular organelles, have also been assayed. Correlation is sought between the enzyme activity changes and some other metabolic effects of anesthesia.

Autolysis of glycoproteins in rat kidney lysosomes in vitro. Effects on the isoelectric focusing behaviour of glycoproteins, arylsulphatase and beta-glucuronidase

1. Rat kidney lysosomal glycoproteins, prelabelled in the N-acetylneuraminic acid and polypeptide portions with N-acetyl[(3)H]mannosamine and [(14)C]lysine, or with N-acetyl-[(14)C]glucosamine, were incubated under various conditions. Autolytic cleavage of labelled N-acetylneuraminic acid and peptide was maximum at pH5.0. 2. N-Acetylneuraminic acid was released more rapidly than peptide during incubation at 37 degrees or 4 degrees C at pH5. p-Nitrophenyloxamic acid, an inhibitor of bacterial neuraminidase (Edmond et al., 1966), inhibited the cleavage of N-acetylneuraminic acid and peptide, and also inhibited cathepsin D activity. 3. Galactono-, mannono-, and glucono-lactone, inhibitors of the corresponding glycosidases, blocked the autolytic cleavage of N-acetyl[(14)C]glucosamine and protein without inhibiting beta-N-acetylhexosaminidase or cathepsin D activity. These findings suggest that the carbohydrate side chains protect the polypeptide portion of the lysosomal glycoproteins against proteolytic attack by lysosomal cathepsins. 4. In electrofocusing experiments, autolysis was minimized by adding 0.1% p-nitrophenyloxamic acid to the media used for extraction and electrofocusing, and by maintaining an alkaline pH (pH8.8-9) during extraction and dialysis. Arylsulphatase occurred in two forms with pI values of 4.4 and 6.4-6.7, and beta-glucuronidase in two forms with pI values of 4.4 and 6.1. When [(14)C]lysine and N-acetyl[(3)H]mannosamine were given to rats 1.5 and 1 h before killing, (14)C and (3)H were largely restricted to highly acidic glycoprotein species with pI values of 2.1-5.1. 5. When a lysosomal extract was adjusted to pH5 and incubated at 20 degrees C for 16h and then at 37 degrees C for 1 h before electrofocusing, 32 and 58% of the labelled peptide and N-acetylneuraminic acid was cleaved and the pI values of the labelled glycoproteins were markedly increased. About 80% of the acidic form of arylsulphatase and beta-glucuronidase was recovered with the basic form, and the pI of the basic form of both enzymes rose to 7.0. Similar, though less marked changes, were observed when a lysosomal extract was kept at pH5 for 2h at 4 degrees C before electrofocusing. 6. When an acidic lysosomal fraction (pI4.2-4.6) was incubated at pH5 for 2.5h and refocused, 80% of the arylsulphatase now occurred in two forms with pI values of 5 and 6.4. When a basic lysosomal fraction (pI5.8-6.4) was similarly incubated, the pI of arylsulphatase increased from 6.4 to 7.2. The relative increase in pI of arylsulphatases was accompanied by a proportional loss of N-acetylneuraminic acid from the glycoprotein associated with these forms. 7. These experiments show that lysosomal glycoproteins and two representative hydrolases, when exposed to a mildly acidic pH, readily undergo autolytic degradation and their pI values increase. These observations may have a bearing on the origin of the molecular heterogeneity of the lysosomal enzymes.