scholarly journals Protein phosphatase PP2C in the flagellum of Leishmania major: cloning and characterization

2017 ◽  
Vol 3 ◽  
Author(s):  
A. R. Escalona-Montaño ◽  
R. Pérez-Montfort ◽  
N. Cabrera ◽  
R. Mondragón-Flores ◽  
D. E. Vélez-Ramírez ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Protein Phosphatase ◽  
Protein Concentration ◽  
Leishmania Major ◽  
Polyclonal Antibodies ◽  
Divalent Cations ◽  
Tyrosine Phosphatase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Phosphatase Inhibitors

AbstractThe main goal of this work consisted in cloning, purifying and characterizing a protein phosphatase 2C (PP2C) from promastigotes ofLeishmania major. The gene was cloned and amplified by PCR using specific oligonucleotides and the recombinant protein was purified by affinity chromatography. The peak with maximal protein concentration was analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and revealed a protein of 44·9 kDa with PP2C activity. This activity was dependent on divalent cations (Mg+2and Mn+2) and was optimal at pH of 8·5, using phosphothreonine as the substrate. Sanguinarine inhibited the activity of the recombinantLmPP2C, while protein tyrosine phosphatase inhibitors had no effect. The recombinantLmPP2C was used to generate polyclonal antibodies. These antibodies recognized a protein of 44·9 kDa in differentLeishmaniaspecies; theLmPP2C was localized in the flagellar pocket and the flagellum of promastigotes.

Design and Biological Evaluation of Novel Imidazolyl Flavonoids as Potent and Selective Protein Tyrosine Phosphatase Inhibitors

2020 ◽  
Vol 16 (4) ◽  
pp. 563-574 ◽  
Author(s):  
Rong Y. Han ◽  
Yu Ge ◽  
Ling Zhang ◽  
Qing M. Wang
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Structural Features ◽  
Biological Evaluation ◽  
Cell Protein ◽  
Phosphatase Inhibitors ◽  
Protein Tyrosine ◽  
Therapeutic Development ◽  
Chemical Studies

Background: Protein tyrosine phosphatases 1B are considered to be a desirable validated target for therapeutic development of type II diabetes and obesity. Methods: A new series of imidazolyl flavonoids as potential protein tyrosine phosphatase inhibitors were synthesized and evaluated. Results: Bioactive results indicated that some synthesized compounds exhibited potent protein phosphatase 1B (PTP1B) inhibitory activities at the micromolar range. Especially, compound 8b showed the best inhibitory activity (IC50=1.0 µM) with 15-fold selectivity for PTP1B over the closely related T-cell protein tyrosine phosphatase (TCPTP). Cell viability assays indicated that 8b is cell permeable with lower cytotoxicity. Molecular modeling and dynamics studies revealed the reason for selectivity of PTP1B over TCPTP. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity. Conclusion: Compound 8b should be a potential selective PTP1B inhibitor.

Structure-Based Design and Discovery of Protein Tyrosine Phosphatase Inhibitors Incorporating Novel Isothiazolidinone Heterocyclic Phosphotyrosine Mimetics

2005 ◽  
Vol 48 (21) ◽  
pp. 6544-6548 ◽  
Author(s):  
Andrew P. Combs ◽  
Eddy W. Yue ◽  
Michael Bower ◽  
Paul J. Ala ◽  
Brian Wayland ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Phosphatase Inhibitors ◽  
Protein Tyrosine

scholarly journals Development of Molecular Probes for Second-Site Screening and Design of Protein Tyrosine Phosphatase Inhibitors

2007 ◽  
Vol 50 (9) ◽  
pp. 2137-2143 ◽  
Author(s):  
Jesus Vazquez ◽  
Lutz Tautz ◽  
Jennifer J. Ryan ◽  
Kristiina Vuori ◽  
Tomas Mustelin ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Molecular Probes ◽  
Phosphatase Inhibitors ◽  
Protein Tyrosine

scholarly journals Identification of Phomoxanthone A and B as Protein Tyrosine Phosphatase Inhibitors

ACS Omega ◽  
2020 ◽  
Vol 5 (40) ◽  
pp. 25927-25935
Author(s):  
Runlei Yang ◽  
Qian Dong ◽  
Huibin Xu ◽  
XueHui Gao ◽  
Ziyue Zhao ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Phosphatase Inhibitors ◽  
Protein Tyrosine

scholarly journals A 13-mer peptide straddling the leucine33/proline33 polymorphism in glycoprotein IIIa does not define the PLA1 epitope

Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 1964-1969 ◽  
Author(s):  
F Flug ◽  
R Espinola ◽  
LX Liu ◽  
C SinQuee ◽  
R DaRosso ◽  
...  
Keyword(s):  
Amino Acid ◽  
Polyclonal Antibodies ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Adenosine Diphosphate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Amino Acid Polymorphism ◽  
Glycoprotein Iiia ◽  
Polymerase Chain ◽  
Induced Aggregation

Abstract We confirm the recent report (J Clin Invest 83:1778, 1989) of a polymorphism at amino acid 33 of platelet GPIIIa associated with the PLA1/PLA2 phenotype by using the polymerase chain reaction on cDNA derived from platelet RNA, using the base-pair primers 105–129 and 452- 428. Platelet cDNA from three PLA2-homozygous individuals, when digested with Nci I, gave two bands of 256 bp and 91 bp, whereas eight PLA1 cDNAs gave a single band of 347 bp. Two 13-mer amino acid peptides straddling the amino acid polymorphism: SDEALP (L/P) GSPRCD were synthesized for epitope studies. Two mouse polyclonal antibodies were raised: one against the PLA1-associated peptide, the other against the PLA2 peptide. Both antibodies react with either peptide, as well as with both PLA1 and PLA2 platelets. The PLA1 peptide did not block the binding of two different human anti-PLA1 antibodies to the 100-Kd GPIIIa band on immunoblot of platelet extracts; neither did it block the binding of the same antibodies to PLA1-platelet extracts in an enzyme-linked immunosorbent assay. Further studies were performed on the PLA1 epitope following subtilisin digestion of purified GPIIIa. A 55-Kd fragment was obtained that retained the PLA1 epitope as well as the first 13 N-terminal amino acids of GPIIIa. Reduction of the 55-Kd fragment resulted in loss of the PLA1 epitope with production of a 67- Kd, 21-Kd, and 10-Kd band on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The 55-Kd band does not react with LK-2, a monoclonal antibody versus GPIIIa that inhibits adenosine diphosphate, collagen, epinephrine, and thrombin-induced aggregation. Thus, the PLA1 epitope is conformation-induced, resides on an N-terminal 55-Kd fragment composed of two or more peptides held together by -SH bonds, and is not required for platelet aggregation.

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