scholarly journals Phosphohistidine and phospholysine phosphatase activities in the rat: potential protein-lysine and protein-histidine phosphatases?

1993 ◽  
Vol 296 (2) ◽  
pp. 293-296 ◽  
Author(s):  
C Wong ◽  
B Faiola ◽  
W Wu ◽  
P J Kennelly
Keyword(s):  
Heat Stability ◽  
Specific Protein ◽  
High Molecular Mass ◽  
Bivalent Metal ◽  
Phosphatase Activities ◽  
Phosphoamino Acids ◽  
Tissue Extracts ◽  
Bivalent Metal Ions ◽  
Rat Tissue ◽  
Histidine Phosphatases

We have detected phosphohistidine and phospholysine phosphatase activities in rat tissue extracts using partially phosphorylated, high-molecular-mass (> 10 kDa) polymers of histidine and lysine as substrates. Multiple phosphohistidine- and phospholysine-specific phosphatases were present in these extracts based on observed differences in heat stability, sensitivity to bivalent metal ions and thiol modifying reagents, and/or elution from DE-52 cellulose. The properties of these phosphohistidine and phospholysine phosphatases were distinct from those of the phosphomonoester-specific protein phosphatases or the N-P phosphohydrolases that act on the free phosphoamino acids phosphoarginine, 3-phosphohistidine or phospholysine.

scholarly journals Augmentation of ACTH-induced steroidogenesis in isolated rat adrenal cells by rat tissue extracts and by hormone preparations.

1982 ◽  
Vol 29 (2) ◽  
pp. 251-254 ◽  
Author(s):  
SAYOMI IIDA ◽  
KEIKO MATSUYAMA ◽  
YOSHIHARU ITOH ◽  
KANAME MORIWAKI ◽  
SEIICHIRO TARUI ◽  
...  
Keyword(s):  
Adrenal Cells ◽  
Tissue Extracts ◽  
Rat Tissue ◽  
Isolated Rat

scholarly journals Carboxymethylation of nuclear protein serine/threonine phosphatase X

1997 ◽  
Vol 327 (2) ◽  
pp. 481-486 ◽  
Author(s):  
Susanne KLOEKER ◽  
C. Jeffrey BRYANT ◽  
Stefan STRACK ◽  
J. Roger COLBRAN ◽  
E. Brian WADZINSKI
Keyword(s):  
Polyclonal Antibodies ◽  
Alkali Treatment ◽  
Homologous Protein ◽  
Tissue Extracts ◽  
Cell Extracts ◽  
Nuclear Extracts ◽  
C Terminus ◽  
Phosphatase 2A ◽  
Internal Peptide ◽  
Rat Tissue

Specific rabbit polyclonal antibodies against peptides corresponding to the highly homologous protein serine/threonine phosphatase 2A and X catalytic subunits (PP2A/C and PPX/C respectively) were used to investigate the cellular and subcellular distribution of PP2A/C and PPX/C, as well as their methylation state. Immunoblots of rat tissue extracts revealed a widespread distribution of these enzymes but particularly high levels of PP2A/C and PPX/C in brain and testes respectively. In addition, immunoblots of subcellular fractions and immunocytochemical analyses of rat brain sections demonstrated that PPX/C is predominantly localized to the nucleus, whereas PP2A/C is largely cytoplasmic. Treatment of nuclear extracts with alkali resulted in increased PPX/C immunoreactivity to a polyclonal antibody directed against the C-terminus; no change in PPX immunoreactivity was observed using an antibody against an internal peptide. Alkali treatment of brain and liver cytosolic and nuclear extracts did not change the molecular mass or the isoelectric point of PPX/C. Furthermore, tritiated PPX/C was immunoprecipitated from COS cell extracts incubated with the methyl donor S-adenosyl-l-[methyl-3H]methionine. Thus the increase in immunoreactivity probably results from removal of a carboxymethyl group from PPX/C, as has been shown previously for PP2A/C [Favre, Zolnierowicz, Turowski and Hemmings (1994) J. Biol. Chem. 269, 16311-16317]. Together, our results indicate that the PPX catalytic subunit is a predominantly nuclear phosphatase and is methylated at its C-terminus.

scholarly journals Separation and properties of two arylamidases from rat cardiac-muscle extracts

1977 ◽  
Vol 163 (3) ◽  
pp. 565-570 ◽  
Author(s):  
A F Bury ◽  
T Coolbear ◽  
C R Savery
Keyword(s):  
Metal Ions ◽  
Cardiac Muscle ◽  
Rat Heart ◽  
Bivalent Metal ◽  
Ph Optimum ◽  
Minor Peak ◽  
Bivalent Metal Ions ◽  
Stimulation Of

Two main arylamidase activities were separated from a particle-free supernatant of rat heart by chromatography on DEAE-Sephadex. Although both enzymes hydrolysed L-leucine 4-nitroanilide, only peak-II enzyme hydrolysed L-lysine 4-nitroanilide. A third minor peak (Ia) contained an enzyme that was active mainly on the L-lysine 4-nitroanilide. The mol.wts. of the enzymes in peaks I and II were approx. 257000 and 105000 respectively. The pH optimum was approx. pH7.0 for peak-I enzyme and 7.0-8.0 for peak-II enzyme. Both enzymes were inhibited by addition of puromycin, p-hydroxymercuribenzoate, o-phenanthroline and bivalent metal ions. Addition of dithiothreitol resulted in stimulation of both activities. Dialysis against o-phenanthroline resulted in inhibition of peak-I and -II enzymes, but after dialysis against EDTA only peak-II enzyme was inhibited.

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