Different adhesion and migration properties of human HCV29 non-malignant urothelial and T24 bladder cancer cells: role of glycosylation

In tumour cells, alterations in cellular glycosylation may play a key role in their metastatic behaviour. This study used cell lines having very different behaviour in vivo: HCV29 non-malignant transitional epithelium and T24 bladder transitional cell carcinoma. These differences in behaviour might be due in part to differences in cellular glycosylation patterns. Glycan chain analysis of their glycoproteins was performed with the use of specific lectins. The functional role of carbohydrates was studied by treating these cells with swainsonine, an inhibitor of Golgi alpha-mannosidase II, and in vitro adhesion and migration assays. The adhesion of swainsonine-treated HCV29 and T24 cells was increased on fibronectin and type IV collagen by 1.5- and 2-fold, respectively, whereas adhesion on laminin was virtually unchanged after swainsonine-treatment in HCV29 cells and was increased in T24 cells. Swainsonine treatment reduced the rate of T24 cell migration by 20%. We concluded that beta1-6 branched tri- and tetraantennary complex-type glycans have an important function in adhesion and migration in the studied cell lines. These data support the view that oligosaccharides are involved in several steps of the metastatic process.

Rat submandibular gland during the maturation process: changes in enzyme activities, protein and lectin-binding profiles

The total protein glycosylation profile and specific activity of lysosomal enzymes were investigated in rat submandibular glands isolated from very young (1-month), young (1.5-months) and adult rats (3-months) rats. The specific activity of lysosomal hydrolases (i.e. acid phosphatase, arylsulfatases A and B, beta-N-acetyl-D-glucosaminidase, beta-galactosidase and beta-glucuronidase) decreased in parallel to increasing age of the animals. Furthermore, the thermal stability of acid phosphatase and beta-N-acetyl-D-glucosaminidase was influenced by the age of rats. Age-related changes in protein profile regarding the intensity of particular bands as well as the appearance of certain proteins limited to special age groups were also demonstrated as revealed by Coomassie and lectin staining. Moreover, the marked age-related increase in structures Man (alpha1-2, alpha1-3, alpha1-6) Man, Fuc (alpha1-6) GlcNAc as well as Gal (beta1-3) GlcNAc was observed, whereas staining with terminal NeuAc and GlcNAc showed an inverse correlation. The reaction with (beta1-6) branched N-glycans and Gal (beta1-3) Gal structures was limited to 1-month-old rats. No significant changes in a specific reaction with NeuAc (alpha2-3) Gal were observed. We speculate that the observed differences with respect to protein and glycosylation profiles between 1-month-old rats and older ones could be caused by a modification of the diet composition as well as by the functional and morphological maturation of the rat submandibular gland.

Rat submandibular gland during the maturation process: changes in enzyme activities, protein and lectin-binding profiles

The total protein glycosylation profile and specific activity of lysosomal enzymes were investigated in rat submandibular glands isolated from very young (1-month), young (1.5-months) and adult rats (3-months) rats. The specific activity of lysosomal hydrolases (i.e. acid phosphatase, arylsulfatases A and B, beta-N-acetyl-D-glucosaminidase, beta-galactosidase and beta-glucuronidase) decreased in parallel to increasing age of the animals. Furthermore, the thermal stability of acid phosphatase and beta-N-acetyl-D-glucosaminidase was influenced by the age of rats. Age-related changes in protein profile regarding the intensity of particular bands as well as the appearance of certain proteins limited to special age groups were also demonstrated as revealed by Coomassie and lectin staining. Moreover, the marked age-related increase in structures Man (alpha1-2, alpha1-3, alpha1-6) Man, Fuc (alpha1-6) GlcNAc as well as Gal (beta1-3) GlcNAc was observed, whereas staining with terminal NeuAc and GlcNAc showed an inverse correlation. The reaction with (beta1-6) branched N-glycans and Gal (beta1-3) Gal structures was limited to 1-month-old rats. No significant changes in a specific reaction with NeuAc (alpha2-3) Gal were observed. We speculate that the observed differences with respect to protein and glycosylation profiles between 1-month-old rats and older ones could be caused by a modification of the diet composition as well as by the functional and morphological maturation of the rat submandibular gland.

Expression of beta1-integrins and N-cadherin in bladder cancer and melanoma cell lines

Changes in the expression of integrins and cadherins might contribute to the progression, invasion and metastasis of transitional cell cancer of the bladder and of melanomas. The expression of alpha5 (P < 0.001), alpha2 and beta1 (P < 0.05 - P < 0.001) integrin subunits in melanoma cells from noncutaneous metastatic sites (WM9, A375) were significantly increased as compared to cutaneous primary tumor (WM35) and metastatic (WM239) cell lines. These differences might be ascribed to the invasive character of melanoma cells and their metastasis to the noncutaneous locations. The significantly heterogeneous expression of beta1 integrin subunit in two malignant bladder cancer cell lines (T24 and Hu456) and nonsignificant differences in the expression of alpha2, alpha3, and alpha5 subunits between malignant and non-malignant human bladder cell lines do not allow an unanimous conclusion on the role of these intergrin subunits in the progression of transitional cancer of bladder. The adhesion molecule, expressed in all studied melanoma and bladder cell lines, that reacted with anti-Pan cadherin monoclonal antibodies was identified as N-cadherin except in the HCV29 non-malignant ureter cell line. However, neither this nor any other bladder or melanoma cell line expressed E-cadherin. The obtained results imply that the replacement of E-cadherin by N-cadherin accompanied by a simultaneous increase in expression of alpha2, alpha3 and alpha5 integrin subunits clearly indicates an increase of invasiveness of melanoma and, to a lesser extent, of transitional cell cancer of bladder. High expression of N-cadherin and alpha5 integrin subunit seems to be associated with the most invasive melanoma phenotype.

Comparison of the lectin-binding pattern in different human melanoma cell lines

Glycosylation is generally altered in tumour cells in comparison with their normal counterparts. These alterations are thought to be important because they contribute to the abnormal behaviour of cancer cells. Therefore, we have comparatively analysed the glycoproteins in cell extracts from human melanoma (primary site--WM35; metastatic sites-- WM239, WM9 and A375) cell lines using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and lectin staining. The glycoprotein pattern of the WM35 line differed from that of the other cell lines in having less proteins that reacted with Sambucus nigra, Maackia amurensis and Phaseolus vulgaris agglutinins. A glycoprotein of about 70 kDa had a significantly increased reaction with Sambucus nigra agglutinin in all the cell lines from metastatic sites. In the WM9, WM239 and A375 cell lines, additional bands (160-100 kDa) were stained with Phaseolus vulgaris agglutinin, suggesting that cells from metastatic sites contain more glycoproteins with beta1-6 branches. On the other hand, only minor changes in the reaction with Galanthus nivalis agglutinin, a mannose-specific lectin, were detected. Among the proteins showing different lectin staining, one, with an apparent molecular weight of 133 kDa, was recognized by antibodies as N-cadherin. The present results suggest that in human melanoma the expression of branched and sialylated complex type N-oligosaccharides consistently increased in cells from metastatic sites, and support the view that carbohydrates are associated with the acquisition of the metastatic potential of tumour cells.

Affinity chromatography of branched oligosaccharides in rat liver beta-glucuronidase

Rat liver microsomal and lysosomal beta-glucuronidase-derived glycopeptides were obtained by extensive Pronase digestion followed by N-[14C]acetylation and desialylation by neuraminidase treatment. These glycopeptides were studied by sequential chromatography on lectin-affinity columns such as concanavalin A, lentil lectin, Phaseolus vulgaris erythroagglutinin, Ricinus communis agglutinin I, Triticum vulgaris agglutinin, Glycine max agglutinin and Ulex europaeus agglutinin. Using serial lectin affinity chromatography approach combined with neuraminidase treatment allowed us to show the unexpected presence of complex tri- and/or tetraantennary type glycans (40.8 and 17.0% for microsomal and lysosomal enzyme, respectively). Moreover, the application of neuraminidase treatment revealed that complex biantennary type glycans, present on lysosomal beta-glucuronidase, are almost fully sialylated while the same type of glycans present on microsomal enzyme do not contain sialic acid. Furthermore, the results obtained confirmed that microsomal and lysosomal beta-glucuronidases possess high mannose and/or hybrid type glycans (19.6 and 36.6%, respectively), and complex biantennary type glycans (38.9 and 46.4%, respectively).

Differences of alpha3beta1 integrin glycans from different human bladder cell lines

Expression as well as properties of integrins are altered upon transformation. Cell adhesion regulated by integrins is modulated by glycosylation, one of the most frequent biochemical alteration associated with tumorogenesis. Characterisation of carbohydrate moieties of alpha3beta1 integrin on the cultured human bladder carcinoma (T-24, Hu456, HCV 29T) and human normal ureter and bladder epithelium (HCV 29, Hu609) cell lines was carried out after an electrophoresis and blotting, followed by immunochemical identification of alpha3 and beta1 integrin chains and analysis of their carbohydrates moieties using highly specific digoxigenin-labelled lectins. In all the studied cell lines alpha3beta1 integrin was glycosylated although in general each subunit differently. Basic structures recognized in beta1 subunit were tri- or tetraantennary complex type glycans in some cases sialylated (T-24, HCV 29, HCV 29T) and fucosylated (Hu609, HCV 29T). Positive reaction with Phaseolus vulgaris agglutinin and Datura stramonium agglutinin suggesting the presence of beta1-6 branched N-linked oligosaccharides was found in cancerous cell lines (T-24, Hu456) as well as in normal bladder epithelium cells (Hu609). High mannose type glycan was found only in beta1 subunit from Hu456 transitional cell cancer line. On the other hand alpha3 subunit was much less glycosylated except the invasive cancer cell line T-24 where high mannose as well as sialylated tri- or tetraantennary complex type glycans were detected. This observation suggests that changes in glycosylation profile attributed to invasive phenotype are rather associated with alpha3 not beta1 subunit.

Expression of beta1-integrins and N-cadherin in bladder cancer and melanoma cell lines

Changes in the expression of integrins and cadherins might contribute to the progression, invasion and metastasis of transitional cell cancer of the bladder and of melanomas. The expression of alpha5 (P < 0.001), alpha2 and beta1 (P < 0.05 - P < 0.001) integrin subunits in melanoma cells from noncutaneous metastatic sites (WM9, A375) were significantly increased as compared to cutaneous primary tumor (WM35) and metastatic (WM239) cell lines. These differences might be ascribed to the invasive character of melanoma cells and their metastasis to the noncutaneous locations. The significantly heterogeneous expression of beta1 integrin subunit in two malignant bladder cancer cell lines (T24 and Hu456) and nonsignificant differences in the expression of alpha2, alpha3, and alpha5 subunits between malignant and non-malignant human bladder cell lines do not allow an unanimous conclusion on the role of these intergrin subunits in the progression of transitional cancer of bladder. The adhesion molecule, expressed in all studied melanoma and bladder cell lines, that reacted with anti-Pan cadherin monoclonal antibodies was identified as N-cadherin except in the HCV29 non-malignant ureter cell line. However, neither this nor any other bladder or melanoma cell line expressed E-cadherin. The obtained results imply that the replacement of E-cadherin by N-cadherin accompanied by a simultaneous increase in expression of alpha2, alpha3 and alpha5 integrin subunits clearly indicates an increase of invasiveness of melanoma and, to a lesser extent, of transitional cell cancer of bladder. High expression of N-cadherin and alpha5 integrin subunit seems to be associated with the most invasive melanoma phenotype.

Differences of alpha3beta1 integrin glycans from different human bladder cell lines

Expression as well as properties of integrins are altered upon transformation. Cell adhesion regulated by integrins is modulated by glycosylation, one of the most frequent biochemical alteration associated with tumorogenesis. Characterisation of carbohydrate moieties of alpha3beta1 integrin on the cultured human bladder carcinoma (T-24, Hu456, HCV 29T) and human normal ureter and bladder epithelium (HCV 29, Hu609) cell lines was carried out after an electrophoresis and blotting, followed by immunochemical identification of alpha3 and beta1 integrin chains and analysis of their carbohydrates moieties using highly specific digoxigenin-labelled lectins. In all the studied cell lines alpha3beta1 integrin was glycosylated although in general each subunit differently. Basic structures recognized in beta1 subunit were tri- or tetraantennary complex type glycans in some cases sialylated (T-24, HCV 29, HCV 29T) and fucosylated (Hu609, HCV 29T). Positive reaction with Phaseolus vulgaris agglutinin and Datura stramonium agglutinin suggesting the presence of beta1-6 branched N-linked oligosaccharides was found in cancerous cell lines (T-24, Hu456) as well as in normal bladder epithelium cells (Hu609). High mannose type glycan was found only in beta1 subunit from Hu456 transitional cell cancer line. On the other hand alpha3 subunit was much less glycosylated except the invasive cancer cell line T-24 where high mannose as well as sialylated tri- or tetraantennary complex type glycans were detected. This observation suggests that changes in glycosylation profile attributed to invasive phenotype are rather associated with alpha3 not beta1 subunit.

High-mannose-type oligosaccharides from human placental arylsulfatase A are core fucosylated as confirmed by MALDI MS

Despite numerous studies on arylsulfatase A, the structure of its glycans is not well understood. It has been shown that the concentration of arylsulfatase A increases in the body fluids of patients with some forms of cancer, and the carbohydrate component of arylsulfatase A synthesized in tumor tissues and transformed cells undergoes increased sialylation, phosphorylation and sulfation. To understand the significance of any changes in the glycosylation of arylsulfatase A in cancer, it is important to know the structure of its carbohydrate component in normal tissue. In the present study we have analyzed carbohydrate moieties of human placental arylsylfatase A using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blotting on Immobilon P and on-blot deglycosylation using PNGase F for glycan release. Profiles of N-glycans were obtained by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Oligosaccharides were sequenced using specific exoglycosidases, and digestion products were analyzed by MALDI MS and the computer matching of the resulting masses with those derived from a sequence database. Fifty picomoles (6 microg) of arylsulfatase A applied to the gel were sufficient to characterize its oligosaccharide content. The results indicated that human placental arylsulfatase A possesses only high-mannose-type oligosaccharides, of which almost half are core fucosylated. In addition, there was a minor species of high-mannose-type glycan bearing six mannose residues with a core fucose. This structure was not expected since high-mannose-type oligosaccharides basically have not been recognized as a substrate for the alpha1,6-fucosyltransferase.

Changes in glycosylation of rat liver arylsulfatase B in relation to age

The aim of this study was to determine how glycosylation of the rat liver arylsulfatase B was influenced by the age of the animal. The enzyme was purified from a liver lysosomal fraction obtained from male Wistar rats aged 18 days of gestation, 1 week, and 1, 1.5, 3 and 18 months by an affinity chromatography. Examination of the carbohydrate structures was performed after electrophoresis and blotting, followed by a very sensitive detection system with a set of six highly specific digoxygenin-labelled lectins. After densitometric measurement of the intensity of a digoxigenin-labelled lectin binding to arylsulfatase B, it could be stated that, at least, changes in sialylation are related to the growth and development of rats. Sialylation increases while fucosylation slightly decreases with age of the animal.

Age-related profile of beta-N-acetylhexosaminidase glycosylation in rat liver

Beta-N-acetylhexosaminidase was prepared from a liver lysosomal fraction obtained from rats between 18 days of gestation (group I) and 72 weeks of age (groups II-VI). A glycan chain analysis was performed after an electrophoresis and blotting, followed by a very sensitive detection system with highly specific digoxigenin-labelled lectins. The presence of high-mannose/hybrid type glycans, as well as their fucosylated forms was shown in all the experimental groups. Complex-type glycans with terminal sialic acid or galactose were present in all the groups except for 1-week-old rats in which only a positive reaction with lectins from Galanthus nivalis and Aleuria aurantia was observed. Thus it may be assumed that age-related changes in the glycosylation pattern occur on the first days after birth.

Age-related profile of beta-N-acetylhexosaminidase glycosylation in rat liver

Beta-N-acetylhexosaminidase was prepared from a liver lysosomal fraction obtained from rats between 18 days of gestation (group I) and 72 weeks of age (groups II-VI). A glycan chain analysis was performed after an electrophoresis and blotting, followed by a very sensitive detection system with highly specific digoxigenin-labelled lectins. The presence of high-mannose/hybrid type glycans, as well as their fucosylated forms was shown in all the experimental groups. Complex-type glycans with terminal sialic acid or galactose were present in all the groups except for 1-week-old rats in which only a positive reaction with lectins from Galanthus nivalis and Aleuria aurantia was observed. Thus it may be assumed that age-related changes in the glycosylation pattern occur on the first days after birth.

Does glycosylation of lysosomal proteins show age-related changes in rat liver?

We studied the pattern of lectins binding by liver lysosomal proteins from rats between 18 days of gestation and 72 weeks of age. An analysis of the carbohydrate structure was carried out after an electrophoresis and blotting, followed by a very sensitive detection system with highly specific digoxigenin-labelled lectins. The only age-related differences were observed in the reaction with sialic acid--(MAA; Macckia amurensis, SNA; Sambucus nigra) and fucose--(AAA; Aleuria aurantia) specific lectins. Sialylation increased and fucosylation decreased with age. We also observed a specific reaction with Galanthus nivalis (GNA), Phaseolus vulgaris (PHA-L) and peanut agglutinin (PNA), without any significant changes with age.

Tumor cell N-glycans in metastasis

Metastasis accounts for most of deaths caused by cancer. The increasing body of evidence suggests that changes in N-glycosylation of tumor cell proteins such as increased branching, increased sialylation, polysialylation, decreased fucosylation, enhanced formation of Lewis X and sialyl Lewis X antigens are among important factors determining metastatic potential of tumor cell. Most of the adhesion proteins, e.g., integrins, members of immunoglobulin superfamily, and cadherins are heavily N-glycosylated. The other proteins involved in adhesion, like galectins and type-C selectins, recognize N-glycans as a part of their specific ligands. In this review we focus on recent reports concerning the contribution of N-glycosylation of tumor cell adhesion molecules and some selected membrane proteins in the tumor invasion and metastasis.

Characterization of the oligosaccharide component of arylsulfatase B from rat liver

A glycan chain analysis of the total oligosaccharide pool derived from rat liver arylsulfatase B was carried out by. P4 Gel Permeation Chromatography and sequential exoglycosidase digestion. It was found that 71% of rat liver arylsulfatase B oligosaccharides were sialylated. The relative contribution of particular structures in the total glycan pool was as follows: sialylated biantennary complex type glycans with terminal galactose--65%, high-mannose type glycans--15%, biantennary complex type glycans with core fucose and terminal N-acetylglucosamine--5%, O-linked oligosaccharides--3.5%.

Characterization of the oligosaccharide component of arylsulfatase B from rat liver

A glycan chain analysis of the total oligosaccharide pool derived from rat liver arylsulfatase B was carried out by. P4 Gel Permeation Chromatography and sequential exoglycosidase digestion. It was found that 71% of rat liver arylsulfatase B oligosaccharides were sialylated. The relative contribution of particular structures in the total glycan pool was as follows: sialylated biantennary complex type glycans with terminal galactose--65%, high-mannose type glycans--15%, biantennary complex type glycans with core fucose and terminal N-acetylglucosamine--5%, O-linked oligosaccharides--3.5%.

Tumor cell N-glycans in metastasis

Metastasis accounts for most of deaths caused by cancer. The increasing body of evidence suggests that changes in N-glycosylation of tumor cell proteins such as increased branching, increased sialylation, polysialylation, decreased fucosylation, enhanced formation of Lewis X and sialyl Lewis X antigens are among important factors determining metastatic potential of tumor cell. Most of the adhesion proteins, e.g., integrins, members of immunoglobulin superfamily, and cadherins are heavily N-glycosylated. The other proteins involved in adhesion, like galectins and type-C selectins, recognize N-glycans as a part of their specific ligands. In this review we focus on recent reports concerning the contribution of N-glycosylation of tumor cell adhesion molecules and some selected membrane proteins in the tumor invasion and metastasis.

Preliminary characterization of the oligosaccharide component of arylsulfatase B from human placenta

Isoelectric focusing of homogenous arylsulfatase B from human placenta pointed to the presence of enzymatically active and inactive forms of high pI (pH 9-8) and of lower pI (pH 6.5-5.5). Glycan chain analysis performed with the use of a Glycan Differentiation Kit showed that basic forms of arylsulfatase B from human placenta contained mostly high mannose/hybrid type glycans, with 6-O-L-fucose bound to the innermost N-acetylglucosamine residue, whereas acidic forms of the enzyme contained complex type glycans containing fucose and sialic acid. However, the latter forms constitute a small percentage of the total carbohydrate component. Lectin affinity chromatography of the native enzyme confirmed the presence of a core fucose and a sialic acid.

Hyaluronidase in human somatic tissues and urine: polymorphism and the activity in diseases

The polymorphism of hyaluronidase (EC 3.2.1.35) (Hyase) was studied on a hyaluronan-polyacrylamide gel. Liver, placenta, ovary and breast tissue were found to have 7 active isoforms while leukocytes and platelets 5 and fibroblasts displayed no hyaluronidase activity. In serum, synovial fluid and urine soluble the most acidic forms are present. Desialylation showed that most of the hyaluronidase isoforms differ in the content of sialic acid. In patients with rheumatoid arthritis, hyaluronidase activity in the synovial fluid varied from not detectable to very high. A partial deficiency was demonstrated in sera from some patients with dysostosis multiplex without mucopolysacchariduria. In I-cell disease, hyaluronidase activity in serum was as that in controls.

Structural assessment of beta-glucuronidase carbohydrate chains by lectin affinity chromatography

Rat liver beta-glucuronidase was studied by sequential lectin affinity chromatography. beta-Glucuronidase glycopeptides were obtained by extensive Pronase digestion followed by N-[14C]acetylation and desialylation by neuraminidase treatment. According to the distribution of the radioactivity in the various fractions obtained by chromatography on different lectins, and on the assumption that all glycopeptides were acetylated to the same specific radioactivity, a relative distribution of glycan structure types is proposed. The presence of complex biantennary and oligomannose type glycans (56.8% and 42.7%, respectively) was indicated by Concanavalin A-Sepharose chromatography. Ulex europaeus agglutinin-agarose chromatography revealed the presence of alpha(1-3)linked fucose in some of the complex biantennary type glycans (16.6% of the total glycopeptides). Wheat germ agglutinin chromatography indicated that the minority (0.5%) were hybrid or poly (N-acetyllactosamine) type glycans. Furthermore, the absence of O-glycans, tri-, tetra- and bisected biantennary type glycans was demonstrated by analysis of Concanavalin A-Sepharose unbound fraction by chromatography on immobilized soybean agglutinin, Ricinus communis agglutinin and Phaseolus vulgaris erythroagglutinin.

Purification of rat liver arylsulfatase A and its microheterogeneity assayed by crossed affinity-immunoelectrophoresis

Arylsulfatase A (arylsulfatase sulfohydrolase) EC 3.1.6.1 was purified from rat liver by a procedure consisting of differential centrifugation, Con A-Sepharose and Blue Sepharose chromatography, PBE 94 chromatofocusing, DEAE-cellulose and gel filtration chromatography followed by preparative electrophoresis. A molecular mass of 132,000 was estimated by gradient PAGE. Particular proteins were detected by immunoelectrophoresis. Isoelectric focusing combined with immunoelectrophoresis gave two peaks of arylsulfatase A, with isoelectric points of pH 3.9 and 4.5. Microheterogeneity of rat liver arylsulfatase A was studied by affinity immunoelectrophoresis with 9 different lectins. The presence of concanavalin A-, Lens culinaris agglutinin-, Lotus tetragonolobus agglutinin- and wheat germ agglutinin-reactive forms permitted assessment of the types of carbohydrate moieties in arylsulfatase A.

Purification of beta-glucuronidase and structural assessment of the carbohydrate chains by lectin affinity immunoelectrophoresis

The purification of rat liver beta-glucuronidase from a lysosomal fraction by methods including affinity chromatography, chromatofocusing and preparative PAGE steps is described. Molecular weights of 300,000 and 150,000 were estimated by two dimensional gradient PAGE/immunoelectrophoresis of the lysosomal extract. Isoelectrofocusing in agarose gel followed by immunoelectrophoresis in the second dimension revealed the presence of at least five maxima in the range pH 4.3-7.4. The structural assessment of the carbohydrate chains of lysosomal and microsomal beta-glucuronidase was performed by lectin affinity immunoelectrophoresis. Reaction with Concanavalin A indicated the presence of bi-antennary complex, oligomannosidic and hybrid type structures, whereas the absence of tri- and tetra-antennary complex type structures was deduced from the lack of interaction with phytohemagglutinin-L. The reaction with Lens culinaris agglutinin, Pisum sativum agglutinin and Lotus tetragonolobus lectin revealed that part of the glycans contained a fucose alpha(1-6)-linked to the N-acetylglucosamine attached to asparagine. The presence of terminal beta(1-4)-galactose residues was detected with Ricinus communis agglutinin I.

Daily changes of protein synthesis and secretion rates in rat liver slices

The rates of protein synthesis and secretion in rat liver slices showed temporal variability, as assessed by the use of [14C]leucine. The protein synthesis showed daily changes with two maxima at 13:00 and 01:00 hr and minimum at 17:00 hr. The secretion rate also varies within 24 hr showing biphasic pattern. The pattern of daily secretion rate for hydrophobic proteins differed from the pattern observed for acid proteins and glycoproteins.

Temporal changes of acid phosphatase, arylsulphatase, beta-galactosidase and beta-N-acetyl-D-glucosaminidase activities in subcellular fractions of rat liver

In this paper circadian changes in the liver enzyme activities of rat housed under highly standardized conditions with 12: 12 hour light-dark cycle are shown. Activities of acid phosphatase, arylsulphatase, beta-galactosidase and beta-N-acetyl-D-glucosaminidase in microsomal and lysosomal fractions and crude homogenate were estimated every 4 hr during one 24-hr period. The enzyme activities were related to 1 mg of protein, 1 mg of DNA and 1 g fresh tissue. Daily changes of enzyme activities were found. In case of activity calculated per 1 mg DNA two maxima at 0500 and at 2100 hr were observed, while activity calculated per 1 mg protein showed one maximum at 0500 hr. Activity calculated per 1 g fresh tissue showed the maximum at 0500 hr for each enzyme only in microsomal fraction. As far as acrophase table is concerned for all enzymes and fractions the acrophase occurred during the night. The obtained results are discussed in relation to lysosomal enzymes synthesis process as well as different reference values.

Seasonal changes in the circadian activity rhythm of light-dark (LD) and completely dark (DD) regimen in the mouse submandibular gland in the presence of light-dark (LD) and completely dark (DD) regimen

Influence of seasons on circadian activity changes and the influence of one and six weeks of DD upon these changes of acid phosphatase (AP) and beta-acetylglucosaminidase (AM) was studied in the submandibular gland of sexually mature male mice. Total enzyme activity was determined in tissue homogenates at four-hour intervals in March, June, October, and February under standard LD12/12 conditions and after one and six weeks of the DD regime. The rhythms were analysed according to cosinor method. Under constant lighting conditions the seasonal differences in the AM circadian activity rhythm were found. AP activity was considerably less influenced by seasonal changes. Both enzyme activity changes were independent of each other and each rhythm was differently influenced by DD. In the case of AM the most pronounced circadian activity changes had the highest amplitude and mesor occurred in summer. The strongest influence of DD upon this enzyme activity rhythm was observed in spring and summer especially after the first week, after six weeks the acrophase returned to the LD group value (spring). In autumn and winter the reaction to DD was different to that of summer and spring. For AP the circadian changes of activity were non-rhythmic in spring, whereas in all other seasons the acrophases occurred almost at the same time in the afternoon. In DD the activity rhythm significantly changed after six weeks. In all seasons, except spring the circadian rhythm of activity was not observed after six weeks of DD. An attempt was made to explain the observed results by the certain kind of genetic memory present in laboratory animals the neurohormonal system of which is influenced by seasonal changes.

Effect of different lighting conditions on beta-acetylglucosaminidase activity changes in mouse liver as related to locomotor activity

The effect of a 30-minute light stimulus applied at various times of the 24-hour cycle on changes in the activity of beta-acetylglucosaminidase was studied in the liver of male mice. The animals were kept in darkness with the light switched on for 30 minutes from 9 to 9.30 a.m. in two experimental groups and from 9 to 9.30 p.m. in another two groups. The total beta-acetylglucosaminidase activity in the homogenate was determined by the method of Sellinger et al. at intervals of 4 hours after 1 and 4 weeks of this experiment. At the same time, in all groups the locomotor activity of the animals was recorded. The obtained results showed that: 1) under the conditions of this experiment rhythmic changes of beta-acetylglucosaminidase activity persisted evidencing their endogenous origin; 2) the effect produced by light depended on the time of the 24-hour period at which it was applied; 3) the rhythm of locomotor activity seems to be synchronized directly by the light-darkness changes.

The influence of UV on the rhythmic activity of some lysosomal hydrolases in supernatant from mice in parabiosis

The influence of UV radiation on the rhythmic activity of lysosomal hydrolases in parabiotic mouse liver was tested when one partner in parabiosis was irradiated. The enzymatic activity was determined by biochemical methods. Significant differences in the rhythmic activities of the enzymes from both partners in parabiosis were found. It was suggested that the blood might be a mediator which transfers the information of radiation action.

Rhythmic changes of some lysosomal hydrolases activity from rat liver. Rhythmic changes of acid phosphatase synthesis

The activity of acid phosphatase (E.C.3.1.3.2.), arylsulfatase (E.C.3.1.1.23.), beta-galactosidase (E.C.3.1.1.23.), and beta-acetylglucosaminidase (E.C.3.2.1.30.) in rat liver homogenates of 4.5 month-old male rats is presented in this paper. The degradation processes are observed in rat liver homogenate after incubation. The activity of acid phosphatase and beta-acetylglucosaminidase increases, the activity in one of beta-galactosidase is constant, and arylsulfatase decreases during the time of incubation. Furthermore, the maxima of the enzyme activities shift during the incubation in the time of a day. Gel filtration of acid phosphatase on the Sephadex G-150 Superfine and DEAE-cellulose columns determinate the mutual content of acid phosphatase subunits to isoenzymes I and II in various points of a day. The greatest content of acid phosphatase subunits versus both the isoenzymes content is at 02(24), and the greatest content of isoenzyme II versus the content of isoenzymes I appears at 07(12). From these data it is clear that the period of the isoenzyme II synthesis from the subunit amounts to 5 h, while 10 h are necessary to create the isoenzyme I originated from isoenzyme II. The comparison of acid phosphatase activity before and after the homogenate filtration on the Sephadex column indicates the increase of this enzyme activity after its separation from the other proteins and other components.