Application

Useful for the study of enzyme kinetics, regulation, and to dephosphorylate target substrates.

Biochem/physiol Actions

PTPRN (protein tyrosine phosphatase, receptor type N) is cleaved at the cytosolic domain during insulin secretion. The cytosolic domain is relocated to nucleus where it promotes insulin gene transcription. This protein plays important role in hormone and neuropeptide secretion. This protein is crucial in controlling the dense core vesicle number in β cells and glucose-induced and basal insulin release. PTPRN null mice show reduced dense core vesicle (DCV) number, abnormal insulin secretion, female infertility, behavioral alteration, and circadian dysregulation.

General description

Protein tyrosine phosphatase. (PTP-IA2, ICA-512), Catalytic domain, (amino acids 693- 979), (Gene bank accession no. NM_002846), with N-terminal GST tag, MW = 58.8 kDa, expressed in an E. coli expression system.

PTPRN (protein tyrosine phosphatase, receptor type N), more commonly known as IA-2 (insulinoma-associated protein 2), is a transmembrane protein of the PTP family. It was initially identified as a major autoantigen in type-1 diabetes mellitus. In neuroendocrine cells, it resides in the secretory granules. It is a multi-domain protein with intracellular, transmembrane and extracellular domains, and its intracellular region contains a pseudocatalytic domain. It gets processed multiple times during its life cycle, and its different parts are exposed to different cellular and tissue regions such as nucleus, cytosol, organellar lumen in the secretory pathway, extracellular pancreatic islet space, and membrane compartments. This gene is localized to human chromosome 2q35, and codes for a protein of 979 residues.

Physical form

Formulated in 25 mM Tris-HCl, pH 8.0, 75 mM NaCl, 0.05% Tween-20, 50% glycerol, 2 mM EDTA, 1 mM DTT, and 10 mM glutathione.

Preparation Note

Thaw on ice. Upon first thaw, briefly spin tube containing enzyme to recover full content of the tube. Aliquot enzyme into single use aliquots. Store remaining undiluted enzyme in aliquots at -70°C. Note: Enzyme is very sensitive to freeze/thaw cycles.

Unit Definition

One unit will hydrolyze 1 pmol 6, 8-difluoro-4-methyl umbelliferyl phosphate (DiFMUP) per minute at pH 6.3 and 30°C.