Cysteamine S-Phosphoric Acid.

Åkerfeldt, Stig; Willman, Nils-Erik; Berggren, Britt; Thomelius, Hans; Westin, Gertrud

doi:10.3891/acta.chem.scand.14-1980

Cited by 55 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4. Between pH 2 and 12, the rate constants for the hydrolysis of the phospho-group are similar in magnitude to those published for the hydrolysis of butylthiophosphate (23), cysteamine S-phosphoric acid (24), and the thiophosphopeptides derived from IICB Glc (25) and from II Mtl (26). Although the rate constants for hydrolysis of butylthiophosphate and cysteamine S-phosphoric acid exhibit bell-shaped curves in the pH range 1-6, this was not observed with the thiophosphoesters of any of the PTS proteins.…”

Section: Resultssupporting

confidence: 64%

Transient State Kinetics of Enzyme IICBGlc, a Glucose Transporter of the Phosphoenolpyruvate Phosphotransferase System of Escherichia coli

Meadow

Savtchenko

Nezami³

et al. 2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

During translocation across the cytoplasmic membrane of Escherichia coli, glucose is phosphorylated by phospho-IIA Glc and Enzyme IICB Glc , the last two proteins in the phosphotransfer sequence of the phosphoenolpyruvate:glucose phosphotransferase system. Transient state (rapid quench) methods were used to determine the second order rate constants that describe the phosphotransfer reactions (phospho-IIA Glc to IICB Glc to Glc) and also the second order rate constants for the transfer from phospho-IIA to the phosphorylation site Cys of IIB Glc or IICB Glc were found to be 3.5 and 12, respectively. These equilibrium constants signify that the thiophospho-group in these proteins has a high phosphotransfer potential, similar to that of the phosphohistidinyl phosphotransferase system proteins. In these studies, preparations of IICB Glc were invariably found to contain endogenous, firmly bound Glc (estimated K D ϳ10 ؊7 M). The bound Glc was kinetically competent and was rapidly phosphorylated, indicating that IICB Glc has a random order, Bi Bi, substituted enzyme mechanism. The equilibrium constant for the binding of Glc was deduced from differences in the statistical goodness of fit of the phosphotransfer data to the kinetic model.The bacterial phosphoenolpyruvate:glycose phosphotransferase system (PTS) 3 comprises dozens of cytoplasmic and membrane proteins, most of which are the sugar-specific components of the system (for reviews, see Refs. 1-4). The PTS has several important functions in eubacterial cell physiology in addition to its major role in sugar transport, especially in Gram-positive bacteria (5).When the PTS catalyzes sugar transport, the sugar is phosphorylated as it crosses the membrane, and this process requires 3-6 proteins, depending on the sugar. One example is the Glc transport system in enteric bacteria, shown in Fig. 1.The first two proteins, Enzyme I and HPr, are the so-called general proteins of the system, meaning that they are not sugar-specific. The second pair of proteins, IIA Glc and IICB Glc , are the sugar-specific components. In other cases, the sugar-specific proteins vary from one to four separately encoded proteins. All of the phosphotransfer reactions except the last step (transfer to the sugar) are physiologically reversible. A second point is that the phosphorylation site residues in the PTS proteins are generally His, but in a number of the membrane proteins, the phosphorylation site can be a Cys residue. The phosphoryl group is transferred from PEP through a chain of His proteins to the membrane Enzyme II, where the phosphorylation site can be a His or a Cys (as it is in IICB Glc ), and finally to the sugar. In IICB Glc , the B domain extends into the cytoplasm and contains the phosphorylation site Cys.Our long term goal is to be able to predict the kinetics of Glc uptake by intact cells, and for this purpose it is necessary to obtain the rate constants for each of the reactions in Fig. 1. We established the basic methodology by developing a rapid quench method for determini...

show abstract

Section: Resultssupporting

confidence: 64%

Transient State Kinetics of Enzyme IICBGlc, a Glucose Transporter of the Phosphoenolpyruvate Phosphotransferase System of Escherichia coli

Meadow

Savtchenko

Nezami³

et al. 2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…[16][17][18][19] In turn, some chemical properties of S-phosphorylated peptides can be inferred from early studies involving several low molecular S-substituted phosphorothioic acids. 20 In general, this class of compounds is very stable at pH >7 up to 12, 21,22 but is prone to phosphothiolester bond hydrolysis with its maximum rate at a pH of 2-4. At pH <2 hydrolysis slows down according to a mechanism discussed by Åkerfeldt.…”

Section: Stabilitymentioning

confidence: 99%

Puzzling over protein cysteine phosphorylation – assessment of proteomic tools for S-phosphorylation profiling

Buchowiecka

2014

Analyst

View full text Add to dashboard Cite

Cysteine phosphorylation has recently been discovered in both prokaryotic and eukaryotic systems, and is thought to play crucial roles in signaling and regulation of cellular responses. This article explores the topics of chemical stability of this type of structural modification and the resulting issues regarding affinity enrichment of S-phosphopeptides and their mass spectrometry-based detection in the course of general proteomics studies. Together, this work suggests that the current advances in phosphoproteomic methodologies provide adequate tools for investigating protein cysteine phosphorylation and appear to be immediately available for practical implementation. The article provides useful information necessary for designing experiments in the emerging cysteine phosphoproteomics. The examples of methodological proposals for S-linked phosphorylation detection are included herein in order to stimulate development of new approaches by the phosphoproteomic community.

show abstract

“…Alternatively, the phosphate itself could accept the proton, either directly or via WAT1. The pK a2 of free phosphocysteine is about 5.0 (41). The use of the phosphate moiety of a thiophosphate ester to catalyze its own hydrolysis has been proposed for the non-enzymatic hydrolysis of S-nbutylphosphorothioate (42).…”

Section: Table VII Calculated Geometries Of the Midpoint For Three Prmentioning

confidence: 99%

The X-ray Crystal Structures of Yersinia Tyrosine Phosphatase with Bound Tungstate and Nitrate

Fauman

Yuvaniyama

Schubert

et al. 1996

Journal of Biological Chemistry

113

120

View full text Add to dashboard Cite

X-ray crystal structures of the Yersinia tyrosine phosphatase (PTPase) in complex with tungstate and nitrate have been solved to 2.4-Å resolution. Tetrahedral tungstate, WO 4 2؊ , is a competitive inhibitor of the enzyme and is isosteric with the substrate and product of the catalyzed reaction. Planar nitrate, NO 3 ؊ , is isosteric with the PO 3 moiety of a phosphotransfer transition state. The crystal structures of the Yersinia PTPase with and without ligands, together with biochemical data, permit modeling of key steps along the reaction pathway. These energy-minimized models are consistent with a general acid-catalyzed, in-line displacement of the phosphate moiety to Cys 403 on the enzyme, followed by attack by a nucleophilic water molecule to release orthophosphate. This nucleophilic water molecule is identified in the crystal structure of the nitrate complex. The active site structure of the PTPase is compared to alkaline phosphatase, which employs a similar phosphomonoester hydrolysis mechanism. Both enzymes must stabilize charges at the nucleophile, the PO 3 moiety of the transition state, and the leaving group. Both an associative (bond formation preceding bond cleavage) and a dissociative (bond cleavage preceding bond formation) mechanism were modeled, but a dissociative-like mechanism is favored for steric and chemical reasons. Since nearly all of the 47 invariant or highly conserved residues of the PTPase domain are clustered at the active site, we suggest that the mechanism postulated for the Yersinia enzyme is applicable to all the PTPases.

show abstract

Cysteamine S-Phosphoric Acid.

Cited by 55 publications

References 0 publications

Transient State Kinetics of Enzyme IICBGlc, a Glucose Transporter of the Phosphoenolpyruvate Phosphotransferase System of Escherichia coli

Transient State Kinetics of Enzyme IICBGlc, a Glucose Transporter of the Phosphoenolpyruvate Phosphotransferase System of Escherichia coli

Puzzling over protein cysteine phosphorylation – assessment of proteomic tools for S-phosphorylation profiling

The X-ray Crystal Structures of Yersinia Tyrosine Phosphatase with Bound Tungstate and Nitrate

Contact Info

Product

Resources

About