Purification and characterization of the Novikoff hepatoma glycogen phosphorylase and its relations to a fetal form

Sato, Kei; Weinhouse, Sidney

doi:10.1016/0003-9861(73)90439-6

Cited by 23 publications

(8 citation statements)

References 17 publications

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“…Comparative electrophoretic and immunological studies of the enzymes isolated from MH 3924A and ClI cells with those isolated from liver and brain showed that the enzyme expressed in the two cell lines exhibited characteristics similar to those of the brain isoenzyme, which, on the other hand, has been described to be closely related to the enzyme expressed in fetal liver or in 14-day whole embryo [15,[20][21][22]. The enzymes from the cell lines and from brain could easily be separated electrophoretically from the liver enzyme in native homogeneous and gradient gels, owing to differences in mobility (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Some years ago, Sato and co-workers [2,[20][21][22] described the occurrence of a phosphorylase isoenzyme in transplantable rat hepatomas, which was different from the liver isoenzyme but exhibited similar electrophoretic mobility to the brain-or fetaltype enzyme, and cross-reaction with antibodies raised against the brain isoenzyme. So far, only the b-form of the phosphorylase isoenzyme from Novikoff hepatoma has been isolated and partly characterized biochemically and immunologically [21,22]; extracts from other hepatomes, e.g.…”

Section: Introductionmentioning

confidence: 99%

“…So far, only the b-form of the phosphorylase isoenzyme from Novikoff hepatoma has been isolated and partly characterized biochemically and immunologically [21,22]; extracts from other hepatomes, e.g. Morris hepatoma (MH) 3924A, have been used for immunological studies [22].…”

Section: Introductionmentioning

confidence: 99%

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Glycogen phosphorylase isoenzymes from hepatoma 3924A and from a non-tumorigenic liver cell line. Comparison with the liver and brain enzymes

Mayer

Seelmann-Eggebert

Letsch

1992

Biochemical Journal

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Glycogen phosphorylase isoenzymes were isolated from normal rat liver, rat brain, the glycogen-poor Morris hepatoma (MH) 3924A, and the glycogen-rich non-tumorigenic liver cell line C1I. Electrophoretic and immunological characterization of the enzymes showed that tumour and C1I cells expressed a phosphorylase isoform similar to the brain type; the liver type was not detectable. All enzymes were obtained as dimers; the Mr of the subunits was 96000 (liver), 93000 (brain and MH 3924A) and 92000 (C1I). Isoelectric focusing revealed a main band of pI 6.34 for liver phosphorylase a, pl 5.67 for the enzymes from MH 3924A and brain, and pI 5.68 for CII phosphorylase. Partial kinetic characterization of the AMP-independent forms of the isoenzymes yielded Km values for glucose 1-phosphate of 3.5 + 0.5 mm (liver), 3.9 mm (brain), 1.9 + 0.3 mm (MH 3924A) and 2.5 + 0.5 mm (C1I); Km values for glycogen were 0.4 mM (liver) and 0.3 mm (MH 3924A and C1I), calculated as glucose equivalents. The AMP-independent phosphorylase was inhibited by glucose 6-phosphate (Glc6P) with Ki values of 0.32 + 0.03 mm (C1I), 0.50 + 0.04 mm (MH 3924A) and -5 mM (brain). The inhibition could be abolished by 1 mM-AMP, indicating that AMP and Glc6P may partially compete for the same site on the protein. Liver phosphorylase a was not inhibited by up to 25 mM-Glc6P. In contrast with liver and brain isoenzymes, phosphorylase from the cell lines was not affected by NaF and Na2SO4. The data show that both the hepatocellular carcinoma and the non-malignant immortalized liver cells express a phosphorylase isoform different from the liver type. Furthermore, there is some evidence that the enzyme from MH 3924A and C1I cells is distinct from brain phosphorylase a, in spite of electrophoretic and immunological resemblance, and that this isoenzyme is subject to altered metabolic regulation.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Glycogen phosphorylase isoenzymes from hepatoma 3924A and from a non-tumorigenic liver cell line. Comparison with the liver and brain enzymes

Mayer

Seelmann-Eggebert

Letsch

1992

Biochemical Journal

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“…This enzyme exists as three isoenzymes, namely, the brain (BGP), muscle (MGP), and liver types (LGP) (Henion and Sutherland 1957;Schliselfeld et al 1970;Newgard et al 1988). BGP is the major isoenzyme of GP found in fetal tissues and tumor tissues (Sato and Weinhouse 1973), and it is also present in various adult peripheral tissues (Kato et al 1989). MGP and LGP replace BGP during differentiation of the muscle and liver, respectively (Sato et al 1976).…”

Section: Introductionmentioning

confidence: 99%

Histocytochemical and immunohistochemical studies related to the role of glycogen in human developing digestive organs

et al. 1995

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To elucidate the role of glycogen in the epithelium of developing digestive organs, we investigated the appearance of glycogen and glycogen phosphorylase (GP) in these organs. We studied 64 externally normal human embryos at Carnegie stages 13-23 (5.1-28.0 mm in crown-rump length, 4-8 weeks of gestation) by histocytochemical staining for glycogen and immunohistochemical staining with antibodies against two isoenzymes of GP: brain-type (BGP) and muscle-brain-type (MBGP) GP. At stage 13, glycogen appeared in the epithelium of the digestive tract and the parenchyma of the pancreas. As development advanced, glycogen granules increased in number and size in these tissues, and they became evenly distributed in the epithelium of the digestive tract as either single particles or aggregates, as deduced by electron microscopy at late embryonic stages. Immunoreactivity specific both for BGP and for MBGP was detected in the digestive tract and the pancreas from stage 13. As development advanced, both BGP- and MBGP-immunoreactive cells increased in number and in immunoreactivity, and the number of MBGP-immunoreactive cells became larger than that of BGP-immunoreactive cells. By contrast, in hepatic cells, which serve as a major storage site for glycogen in adults, glycogen was detected only from stage 20, in smaller amounts, without formation of aggregates, and no immunoreactivity specific for BGP or MBGP was apparent throughout the embryonic stages examined. Thus, in the epithelium of the digestive tract and the parenchyma of the pancreas, but not in hepatic cells, the appearance and localization of GP coincided almost exactly with that of glycogen. These observations suggest that glycogen in the epithelium of the digestive tract and the parenchyma of the pancreas has not only been synthesized but also degraded from an early embryonic period and may, thus, be related to active cellular metabolism that is specific for embryonic development, including proliferation of the epithelium and interactions between epithelium and mesenchyme.

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“…This enzyme possesses three isoenzymes, i. e., muscle (MGP), liver (LGP) and brain type (BGP) (3,9,22,24). BGP is the major isoenzyme of phosphorylase found in fetal tissues and tumor tissues (16,17), but is also present in various peripheral tissues (1,24,25). MGP, which replaces BGP during muscle differentiation (17), and LGP are localized in mature skeletal muscles and liver cells, respectively (18).…”

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confidence: 99%

Mode of expression of brain- and muscle-type glycogen phosphorylase in extraocular muscles of human embryos.

Oguni

1991

Acta Histochem. Cytochem

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The appearance of two molecular markers of muscle differentiation, brain (BGP) and muscle-brain (MB-GP) type of glycogen phosphorylase, was studied immunohistochemically in the extraocular muscles of human embryos (Carnegie stages 13 to 23). During stages 13-18, there was no immunoreactivity to BGP and MB-GP antibodies around the optic vesicle. At stage 20, myogenic cells around the optic vesicle became immunoreactive to both BGP and MB-GP antibodies, however, the number of MB-GP immunoreactive cells was larger than that of BGP immunoreactive cells. At stage 21, MB-GP immunoreactive cells increased in number, but BGP immunoreactive cells decreased. At stage 23, BGP immunoreactivity disappeared from the extraocular muscles. These findings suggest that BGP appears transiently in a restricted population of extraocular muscles in the embryonic period and the isoenzyme pattern becomes adult type (MGP) in the late embryonic period.

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Purification and characterization of the Novikoff hepatoma glycogen phosphorylase and its relations to a fetal form

Cited by 23 publications

References 17 publications

Glycogen phosphorylase isoenzymes from hepatoma 3924A and from a non-tumorigenic liver cell line. Comparison with the liver and brain enzymes

Glycogen phosphorylase isoenzymes from hepatoma 3924A and from a non-tumorigenic liver cell line. Comparison with the liver and brain enzymes

Histocytochemical and immunohistochemical studies related to the role of glycogen in human developing digestive organs

Mode of expression of brain- and muscle-type glycogen phosphorylase in extraocular muscles of human embryos.

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