Are protein-tyrosine phosphatases specific for phosphotyrosine?

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Protein-tyrosine phosphatases (PTPases) are believed to exhibit restricted specificity toward phosphotyrosine. I demonstrate here that both the Yersinia PTPase and rat PTP1 can dephosphorylate alkyl phosphates such as flavin mononucleotide, pyridoxal 5'-phosphate, D-glucose 6-phosphate, DL-α- glycerophosphate, O-phospho-L-serine, and O-phospho-L-threonine. The k(cat) values for alkyl phosphates are orders of magnitude slower than those for aryl phosphates such as p-nitrophenyl phosphate and O-phospho-L-tyrosine, reflecting the intrinsic lower chemical reactivity of the alkyl phosphates. In addition, the k(cat) values for the PTPase-catalyzed hydrolysis of alkyl phosphates are similar to the k(cat) values for the PTPase-catalyzed 18O exchange reaction between inorganic phosphate and water. I conclude that the rate-limiting step for the hydrolysis of alkyl phosphates has changed to the phosphorylation of the PTPases, i.e. the formation of the phosphoenzyme intermediate. The implications of the results described in this report in terms of studying the PTPase catalytic mechanism and their potential application in developing selective PTPase inactivators are discussed.

Original languageEnglish (US)
Pages (from-to)16052-16055
Number of pages4
JournalJournal of Biological Chemistry
Volume270
Issue number27
StatePublished - 1995
Externally publishedYes

Fingerprint

Phosphotyrosine
Protein Tyrosine Phosphatases
Phosphates
Hydrolysis
Glycerophosphates
Flavin Mononucleotide
Yersinia
Chemical reactivity
Glucose-6-Phosphate
Phosphorylation
Pyridoxal Phosphate
Threonine
Serine
Rats
Glucose
Water

ASJC Scopus subject areas

  • Biochemistry

Cite this

Are protein-tyrosine phosphatases specific for phosphotyrosine? / Zhang, Zhong-Yin.

In: Journal of Biological Chemistry, Vol. 270, No. 27, 1995, p. 16052-16055.

Research output: Contribution to journalArticle

@article{fca4d68e44234797b592e85c18e69c77,
title = "Are protein-tyrosine phosphatases specific for phosphotyrosine?",
abstract = "Protein-tyrosine phosphatases (PTPases) are believed to exhibit restricted specificity toward phosphotyrosine. I demonstrate here that both the Yersinia PTPase and rat PTP1 can dephosphorylate alkyl phosphates such as flavin mononucleotide, pyridoxal 5'-phosphate, D-glucose 6-phosphate, DL-α- glycerophosphate, O-phospho-L-serine, and O-phospho-L-threonine. The k(cat) values for alkyl phosphates are orders of magnitude slower than those for aryl phosphates such as p-nitrophenyl phosphate and O-phospho-L-tyrosine, reflecting the intrinsic lower chemical reactivity of the alkyl phosphates. In addition, the k(cat) values for the PTPase-catalyzed hydrolysis of alkyl phosphates are similar to the k(cat) values for the PTPase-catalyzed 18O exchange reaction between inorganic phosphate and water. I conclude that the rate-limiting step for the hydrolysis of alkyl phosphates has changed to the phosphorylation of the PTPases, i.e. the formation of the phosphoenzyme intermediate. The implications of the results described in this report in terms of studying the PTPase catalytic mechanism and their potential application in developing selective PTPase inactivators are discussed.",
author = "Zhong-Yin Zhang",
year = "1995",
language = "English (US)",
volume = "270",
pages = "16052--16055",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "27",

}

TY - JOUR

T1 - Are protein-tyrosine phosphatases specific for phosphotyrosine?

AU - Zhang, Zhong-Yin

PY - 1995

Y1 - 1995

N2 - Protein-tyrosine phosphatases (PTPases) are believed to exhibit restricted specificity toward phosphotyrosine. I demonstrate here that both the Yersinia PTPase and rat PTP1 can dephosphorylate alkyl phosphates such as flavin mononucleotide, pyridoxal 5'-phosphate, D-glucose 6-phosphate, DL-α- glycerophosphate, O-phospho-L-serine, and O-phospho-L-threonine. The k(cat) values for alkyl phosphates are orders of magnitude slower than those for aryl phosphates such as p-nitrophenyl phosphate and O-phospho-L-tyrosine, reflecting the intrinsic lower chemical reactivity of the alkyl phosphates. In addition, the k(cat) values for the PTPase-catalyzed hydrolysis of alkyl phosphates are similar to the k(cat) values for the PTPase-catalyzed 18O exchange reaction between inorganic phosphate and water. I conclude that the rate-limiting step for the hydrolysis of alkyl phosphates has changed to the phosphorylation of the PTPases, i.e. the formation of the phosphoenzyme intermediate. The implications of the results described in this report in terms of studying the PTPase catalytic mechanism and their potential application in developing selective PTPase inactivators are discussed.

AB - Protein-tyrosine phosphatases (PTPases) are believed to exhibit restricted specificity toward phosphotyrosine. I demonstrate here that both the Yersinia PTPase and rat PTP1 can dephosphorylate alkyl phosphates such as flavin mononucleotide, pyridoxal 5'-phosphate, D-glucose 6-phosphate, DL-α- glycerophosphate, O-phospho-L-serine, and O-phospho-L-threonine. The k(cat) values for alkyl phosphates are orders of magnitude slower than those for aryl phosphates such as p-nitrophenyl phosphate and O-phospho-L-tyrosine, reflecting the intrinsic lower chemical reactivity of the alkyl phosphates. In addition, the k(cat) values for the PTPase-catalyzed hydrolysis of alkyl phosphates are similar to the k(cat) values for the PTPase-catalyzed 18O exchange reaction between inorganic phosphate and water. I conclude that the rate-limiting step for the hydrolysis of alkyl phosphates has changed to the phosphorylation of the PTPases, i.e. the formation of the phosphoenzyme intermediate. The implications of the results described in this report in terms of studying the PTPase catalytic mechanism and their potential application in developing selective PTPase inactivators are discussed.

UR - http://www.scopus.com/inward/record.url?scp=0029005759&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029005759&partnerID=8YFLogxK

M3 - Article

C2 - 7541792

AN - SCOPUS:0029005759

VL - 270

SP - 16052

EP - 16055

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 27

ER -