Product Name

Phosphorylase b from rabbit muscle

Synonym

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

Assay

≥20 units/mg protein

CAS Number

9012-69-5

Molecular Weight

mol wt 97,200 Da by calculation

MDL number

MFCD00131905

Suitability

BioReagent

l Physical and Chemical Information

Appearance

lyophilized powder

Physical form

Lyophilized powder containing lactose, 5′-AMP, and Mg(OAc)² (10 μmole per 100 mg protein)

l Biological Information

Biochem/Physiol Actions

Phosphorylase b is a non-active form and is present in resting muscle. Phosphorylase b kinase activity increases significantly when the Mg₂₊:ATP ratio exceeds 1. The breakdown of ATP during muscle contraction is thought to trigger in vivo conversion of phosphorylase b into a. Phosphorylase b is activated by inosine monophosphate.

Application

Phosphorylase b is used to study the conversion mechanism of inactive phosphorylase b to active phosphorylase in muscle. Phosphorylase b is used to study which factors influence the conversion of phosphorylase b to phosphorylase a such as temperature, AMP, fluoride and detergents. It is used to study phosphorylase b deficiency mutations.The enzyme from Sigma has been used in the calibration of Sepharose C1-6B columns while studying the molecular weight of methylamine dehydrogenase subunits. It has been used in ion mobility-mass spectrometry studies of phosphorylase B ions that have been generated with supercharging reagents, in charge-reducing buffer. It has also been used for the preparation of p₃₂labeled phosphorylase A using phosphorylase kinase and [₃₂P]ATP.

Unit Definition

One unit will form 1.0 μmole of α-D-glucose 1-phosphate from glycogen and orthophosphate in the presence of 5′-AMP, 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 approx. 45 Cori units.)

l Storage

Storage temp.

-20°C

l Precautions and Disclaimer

This product is for R&D use only, not for drug, household, or other uses.

l References

1. http://www.drugbank.ca

2. https://ncit.nci.nih.gov

3. https://www.ncbi.nlm.nih.gov