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P1261

Sigma-Aldrich

Phosphorylase a from rabbit muscle

lyophilized powder, 20-30 units/mg protein

Synonym(s):

1,4-α-D-Glucan:orthophosphate α-D-glucosyltransferase

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About This Item

CAS Number:
9032-10-4
Enzyme Commission number:
2.4.1.1 (BRENDA, IUBMB)
EC Number:
232-878-8
MDL number:
MFCD00167428
UNSPSC Code:
12352204
NACRES:
NA.54
Pricing and availability is not currently available.

biological source

rabbit muscle

Quality Level

200

form

lyophilized powder

specific activity

20-30 units/mg protein

purified by

2× crystallization

composition

Protein, 30-60% E1%/280

foreign activity

AMP-phosphatase, ATP-phosphatase, debrancher enzyme and phosphorylase phosphatase ≤0.1%
phosphoglucomutase ≤0.25%
phosphorylase b ≤30%

storage temp.

−20°C

General description

Phosphorylase A is the active form of glycogen phosphorylase which converts glycogen and orthophosphate (Pi) to glucose 1-phoshate (G-1-P). [1]

Application

Phosphorylase a from rabbit muscle has been used to mix with glycogen for the preparation of limit dextrin.[2] It has also been used to probe the array in oligosaccharide microarray analysis of phosphorylase activity.[3]
Phosphorylase from rabbit muscle has been used in a study to assess the molecular mechanisms of oleanolic acid. [4] It has also been used in a study to describe the conversion of phosphorylase B to A, through a conversion enzyme in the presence of 32P-ATP. [5]

Biochem/physiol Actions

Dimeric phosphorylase b is converted to the more active tetramer, phosphorylase a, by the action of phosphorylase kinase.
Phosphorylase A can be inhibited by these compounds: Polychlorinated biphenyls, polychlorinated biphenylols and polybrominated biphenyls. [6]
Phosphorylase participates in glycogenolysis. Deficiency of phosphorylase leads to several glycogen storage diseases with hepatomegaly.[7]

Unit Definition

One unit will form 1.0 μmole of α-D-glucose 1-phosphate from glycogen and orthophosphate per min at pH 6.8 at 30 °C, measured in a system containing phosphoglucomutase, NADP, and glucose-6-phosphate dehydrogenase. (One μmolar unit is equivalent to ~45 Cori units.)

Physical form

Lyophilized powder containing β-glycerophosphate and EDTA

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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Certificates of Analysis (COA)

Lot/Batch Number
0000316670
0000316670
SLCG7349
SLBT4463
SLBD2837V

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Activity of porcine muscle glycogen debranching enzyme in relation to pH and temperature
Kyla-Puhju M, et al.
Meat Science, 69(1), 143-149 (2005)
Hypoglycemia in the toddler and child
Pediatric Endocrinology, Diabetes, and Metabolism, 920-955 (2014)
Ian J Tetlow et al.
The Plant cell, 16(3), 694-708 (2004-02-20)
Protein phosphorylation in amyloplasts and chloroplasts of Triticum aestivum (wheat) was investigated after the incubation of intact plastids with gamma-(32)P-ATP. Among the soluble phosphoproteins detected in plastids, three forms of starch branching enzyme (SBE) were phosphorylated in amyloplasts (SBEI, SBEIIa
Glycogen Phosphorylase Structures and Function
Fletterick, R. and S. Sprang
Accounts of Chemical Research, 15, 361-369 (1982)
R C Mead et al.
Biochimica et biophysica acta, 701(2), 173-179 (1982-02-18)
Polychlorinated biphenyls, polychlorinated biphenylols and polybrominated biphenyls inhibited both rabbit muscle phosphorylase a and phosphorylase b (1,4-alpha-D-glucan:orthophosphate alpha-d-glucosyltransferase, EC 2.4.1.1). The degree of inhibition was dependent upon the relative hydrophobicity of the compounds and steric hinderance. 2,4,5,2',4',5'-Hexabromobiphenyl and Firemaster BP-6
View All Related Papers

Questions

1–8 of 8 Questions  

  1. What is the buffer required for the enzyme activity?

    1 answer

    1. The final buffer that this product is in prior to lyophilization is 0.1 M B-glycerophosphate and 4 mM EDTA.
      A stock solution can be prepared in 40 mM glycerophosphate buffer, pH 6.8, containing 1 mM EDTA and 5 mM cysteine. EDTA is a chelating agent of copper and other metal ions, which causes oxidation of the protein. The presence of cysteine is to maintain the critical sulfhydryl group in the protein in the reduced state.
      When preparing a stock solution for assaying the activity, a 0.25 unit/ml solution of the protein in 40 mM glycerophosphate buffer, pH 6.8, at 30 °C containing 80 mM cysteine is used.

      Helpful?

  2. How is Phosphorylase A, Product P1261, prepared?

    1 answer

    1. To prepare Phosphorylase A (P1261), Sigma uses a method similar to the one described in the J. Biol.Chem., 231, 65 (1958).

      Helpful?

  3. What is the molecular weight of Phosphorylase A, Product P1261?

    1 answer

    1. The molecular weight of Rabbit Phosphorylase A (tetramer) is 370,000 per Biochemistry 6 (1967) p. 3315 (which was determined by sedimentation and "experiments in a variety of buffers, temperatures, and ionic strength").  The molecular weight by sequence analysis (Proc. Natl. Acad. Sci. USA, 74, 4762-4766) is 97,412.

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  4. What is the pI of Phosphorylase A, Product P1261?

    1 answer

    1. The pI of Phosphorylase A (P1261) is 5.6 - 5.8.

      Helpful?

  5. What is the Department of Transportation shipping information for this product?

    1 answer

    1. Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.

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  6. What is the solubility of Phosphorylase A, Product P1261?

    1 answer

    1. Sigma tests solubility of Phosphorylase A (P1261) in water at a concentration of 1 mg/ml.

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  7. Has the amino acid sequence of phosphorylase from rabbit muscle been published?

    1 answer

    1. The sequence has been published. The amino acid composition is:Asp5l, Asn45, Thr35, Ser29, Glu64, Gln31, Pro36, Gly48, Ala63, Cys9, Val62, Met2l, Ile49, Leu79, Tyr36, Phe38, Trp12, Lys48, HiS22, and Arg63. Reference for the sequence and amino acid composition: K. Titani et al., Proc. Nat. Acad. Sci., USA, 74, 4762-4766 (1977) (see attached pdf).Product P1261 is phosphorylase a, which is the tetrameric form. Products P4649 and P6635 are phosphorylase b, the dimeric  form. The sequence information of the subunit would be the same for both forms.

      Helpful?

  8. What is the final buffer Phosphorylase A, Product P1261, is in prior to lyophilization?

    1 answer

    1. The final buffer Phosphorylase A (P1261) is in prior to lyophilization is 0.1MB-glycerophosphate and 4 mM EDTA.

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