Abstract A glycoprotein phosphotyrosyl protein phosphatase is isolated from human tissues, such as human placental membrane. Upon membrane solubilization and extraction of the enzyme it was subjected to chromatographic purification and isolation. The analytical and biological responses of the enzyme demonstrate that it is novel and readily distinguished from other enzymes previously isolated from similar tissues. The enzyme is a dephosphorylation enzyme of membrane phosphoprotein kinases, and as such has utility as an antidiabetic agent, an antiatherosclerosis agent or an antitumor agent since certain membrane receptor kinases involved in each such biological function involve a phosphorylation mechanism for cell transformation, metabolism and growth and which, when blocked by the instant enzyme, results in a suppression or alteration of the biological function.
Inventors
👤 Theming Liang
👤 Eve E. Slater
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-23 20:16
CPC Classifications
C; C12; C12N; C12N9/00; C12N9/14; C12N9/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
A human phosphotyrosyl protein phosphatase enzyme characterized in having a molecular weight of approximately 200,000 as determined by gel filtration high pressure liquid chromatography; a subunit molecular weight of approximately 73,000 as shown by SDS reducing gel electrophoresis; being a dephosphorylating enzyme with characterizing percentage inhibition of dephosphorylation in the present of phosphatase inhibitors as follows: ______________________________________
10 μM molybdate
- 96.4%
5 mM L-tartrate
- 98.1%
5 mM NaF - 96.7%
20 mM EDTA +78.9
100 μM ZnCl.sub.2
- 14.9
10 μM Vanadate
- 38.2
10 mM p-tyrosine
- 21.6
10 mM p-serine +73.4
______________________________________ an SDS gel electrophoresis substantially as shown in FIG. 6; a pH profile using 32 P-Tyr angiotensin II and PNPP as substrates substantially as shown in FIG. 7; a rate of dephosphorylation of 32 P-Tyr-casein and 32 P-Ser-casein substantially as shown in FIG. 8; and an immunological profile substantially as shown in FIG. 9.
Claim 2
Dependent Claim
150 words
A human phosphotyrosyl protein phosphatase enzyme characterized in having a molecular weight of approximately 200,000 as determined by gel filtration high pressure liquid chromatography; a subunit molecular weight of approximately 73,000 as shown by SDS reducing gel electrophoresis; being a dephosphorylating enzyme with characterizing percentage inhibition of dephosphorylation in the present of phosphatase inhibitors as follows: ______________________________________
10 μM molybdate
- 96.4%
5 mM L-tartrate
- 98.1%
5 mM NaF - 96.7%
20 mM EDTA +78.9
100 μM ZnCl.sub.2
- 14.9
10 μM Vanadate
- 38.2
10 mM p-tyrosine
- 21.6
10 mM p-serine +73.4
______________________________________ an SDS gel electrophoresis substantially as shown in FIG. 6; a pH profile using 32 P-Tyr angiotensin II and PNPP as substrates substantially as shown in FIG. 7; a rate of dephosphorylation of 32 P-Tyr-casein and 32 P-Ser-casein substantially as shown in FIG. 8; and an immunological profile substantially as shown in FIG. 9.
Claim 3
Dependent Claim
19 words
The human phosphotyrosyl protein phosphatase enzyme of claim 1 which is isolated from human tissues high in insulin receptors.
Claim 4
Dependent Claim
20 words
The human phosphotyrosyl protein phosphatase enzyme of claim 2 which is isolated from placental membranes, liver, adipose, brain or muscle.
Claim 5
Dependent Claim
15 words
The human phosphotyrosyl protein phosphatase enzyme of claim 3 which is isolated from placental membranes.