Partial phosphorylation of muscle phosphorylase

Gergely, Pál; G, Bot; Kovács, Elza

doi:10.1016/0005-2744(74)90033-3

Cited by 23 publications

(9 citation statements)

References 8 publications

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“…Gergely and Bot described partially phosphorylated hybrid forms of phosphorylase in rabbit muscle (16,17) and human platelets (18). The activities of these isoenzymes were intermediate between those of phosphorylases b and a. Karpatkin et al (19,20) found that incubation of human platelets with MgATP+ resulted in an increase in total phosphorylase activity and concluded that the data were "consistent with the presence in human platelets of inactive dimer and monomer species of phosphorylase, which require MgATP for activation."…”

mentioning

confidence: 51%

“…In mammalian and nonmammalian tissues, forms ofphosphorylase have been described (16)(17)(18)29) that are less sensitive or insensitive to concentrations ofAMP that maximally activate normal human myophosphorylase. In canine liver (30), human platelets (18,19), and human leucocytes (31), there is a phosphorylase isozyme that remains inactive at concentrations of AMP that maximally activate phosphorylase b.…”

Section: Methodsmentioning

confidence: 99%

“…McArdle phosphorylase required treatment under conditions appropriate for protein phosphorylation before activity could be demonstrated, and the resulting enzyme activity dis- (16,17), and partially phosphorylated inactive isoenzymes may be present in other tissues. However, there is no evidence that human or other mammalian myophosphorylase is regulated by phosphorylation of more than one site.…”

Section: Methodsmentioning

confidence: 99%

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Phosphorylation of McArdle phosphorylase induces activity.

Cerri¹,

Willner²

1981

Proc. Natl. Acad. Sci. U.S.A.

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In McArdle disease, myophosphorylase deficiency, enzyme activity is absent but the presence of an altered enzyme protein can frequently be demonstrated. We have found that phosphorylation of this protein in vitro can result in catalytic activity. We studied muscle of four patients; all lacked myophosphorylase activity, but myophosphorylase protein was demonstrated by immunodiffusion or gel electrophoresis. Incubation of muscle homogenate supernatants with cyclic AMP-dependent protein kinase and ATP resulted in phosphorylase activity. The activated enzyme comigrated with normal human myophosphorylase in gel electrophoresis. Incubation with [y-32P]ATP resulted in incorporation of 32P into the band possessing phosphorylase activity. Activation of phosphorylase by cyclic AMP-dependent protein kinase was inhibited by antibodies to normal human myophosphorylase or by inhibitory protein to cyclic AMP-dependent protein kinase. Incubation of muscle homogenates with phosphorylase b kinase and ATP also resulted in phosphorylase activity. After the action of cyclic AMP-dependent protein kinase, the resulting activity was similar to that ofphosphorylase b. However, incubation with phosphorylase kinase resulted in activity similar

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mentioning

confidence: 51%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Phosphorylation of McArdle phosphorylase induces activity.

Cerri¹,

Willner²

1981

Proc. Natl. Acad. Sci. U.S.A.

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“…On the way of phosphorylating phosphorylase b by the specific kinase, as well as during the dephosphorylation of phosphorylase a by phosphatase, a phospho-dephospho hybrid (phosphorylase ab) is transiently formed (Hurd et al, 1966;Heilmeyer et al, 1970;Bot et al, 1974;Busby & Radda, 1976). This hybrid is enzymatically active and its activity is markedly influenced by ligands (Hurd et al, 1966;Gergely et al, 1974). It has been suggested that phosphorylase ab is a physiologically significant enzyme species (Gergely et al, 1974).…”

mentioning

confidence: 99%

Structural changes in glycogen phosphorylase as revealed by cross-linking with bifunctional diimidates: phospho-dephospho hybrid and phosphorylase a

Dombrádi¹,

Hajdu²,

G³

et al. 1980

Biochemistry

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The technique of cross-linking with a series of bifunctional diimidates (maximal effective length ranging from 3.7 to 14.5 A), followed by dodecyl sulfate gel electrophoresis, was applied to compare the subunit contact areas of phosphorylases b, ab (the phospho-dephospho hybrid), and a and to study the structure and ligand-induced structural changes in phosphorylases ab and a. Similarly to phosphorylase b, the nearest cross-linkable lysyl-NH2 groups are about 3.7 A apart across the intradimer subunit interface (contact m) and about 8 A apart across the interdimer interface (contact d) in both phosphorylases ab and a. The activation of phosphorylase b induced by phosphorylation and that elicited by AMP binding are distinguishable at both contacts m and d. Phosphorylases ab and a tend to form tetramers whose structures are not identical, but AMP renders phosphorylase ab similar to phosphorylase a. Glucose, caffeine, and glycogen are able to dissociate both a and ab tetramers to dimers, whereas glucose 6-phosphate can only dissociate phosphorylase ab. The structure around the nucleotide site of phosphorylase a is rigid so that ligands binding here, such as AMP, ATP, ADP, inosine monophosphate, and glucose 6-phosphate, fail to influence the cross-link pattern. In control, in phosphorylase ab contact m is markedly affected by AMP, ATP, and glucose 1-phosphate; hence, in this respect phosphorylase ab resembles phosphorylase b.

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“…One of the only clues we have to this question comes from work with hybrid a/b phosphorylase. This form of GP, with only one subunit phosphorylated, may be a real phenomenon in vivo {82,83). When tested with PhK, this a/b hybrid was a better substrate for PhK than was phos.…”

mentioning

confidence: 99%

The glycogen phosphorylase/ phosphorylase kinase interaction: effects of mutations in the amino-terminal region of glycogen phosphorylase

Biorn

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Partial phosphorylation of muscle phosphorylase

Cited by 23 publications

References 8 publications

Phosphorylation of McArdle phosphorylase induces activity.

Phosphorylation of McArdle phosphorylase induces activity.

Structural changes in glycogen phosphorylase as revealed by cross-linking with bifunctional diimidates: phospho-dephospho hybrid and phosphorylase a

The glycogen phosphorylase/ phosphorylase kinase interaction: effects of mutations in the amino-terminal region of glycogen phosphorylase

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