Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 2.7.1.40 extracted from

  • Bell, R.A.V.; Storey, K.B.
    Purification and characterization of skeletal muscle pyruvate kinase from the hibernating ground squirrel, Urocitellus richardsonii potential regulation by posttranslational modification during torpor (2018), Mol. Cell. Biochem., 442, 47-58 .
    View publication on PubMed
Search for more literature for 2.7.1.40

Activating Compound

Activating Compound Comment Organism Structure
additional information citrate does not have any effect on PK activity at concentrations up to 10 mM. fructose 1,6-bisphoaphate also shows little propensity to effect PK activity under the conditions of this experiment up to a concentration of 10 mM Urocitellus richardsonii

Inhibitors

Inhibitors Comment Organism Structure
ATP torpid PK is significantly less susceptible to ATP inhibition at 5 and 35°C, with about 5fold and 2fold higher I50 ATP, respectively, as compared to the euthermic values Urocitellus richardsonii
guanidine hydrochloride GnHCl Urocitellus richardsonii
additional information citrate does not have any effect on PK activity at concentrations up to 10 mM. F16P2 also shows little propensity to effect PK activity under the conditions of this experiment up to a concentration of 10 mM Urocitellus richardsonii
Urea
-
 Urocitellus richardsonii

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
 additional information torpid pyruvate kinase (PK) displays a nearly threefold increase in Km PEP as compared to control PK when assayed at 5°C Urocitellus richardsonii
0.025
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 5°C Urocitellus richardsonii
0.033
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 35°C Urocitellus richardsonii
0.048
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii
0.32
-
 ADP purified enzyme, pH 7.0, 5°C Urocitellus richardsonii
0.44
-
 ADP purified enzyme, pH 7.0, 35°C Urocitellus richardsonii
0.57
-
 ADP purified enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii

Metals/Ions

Metals/Ions Comment Organism Structure
K+ activates, torpid PK is significantly more sensitive to KCl with a Ka that is 69% less than the corresponding Ka from the euthermic animal Urocitellus richardsonii
Mg2+ required, no difference between euthermic and torpid PK responses to MgCl2 Urocitellus richardsonii

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
ADP + phosphoenolpyruvate Urocitellus richardsonii
-
 ATP + pyruvate
-
 ?

Organism

Organism UniProt Comment Textmining
Urocitellus richardsonii
-
-
-

Posttranslational Modification

Posttranslational Modification Comment Organism
acylation pyruvate kinase (PK) from the torpid condition is shown to possess nearly twofold acetyl content as compared to control PK Urocitellus richardsonii
phosphoprotein torpid pyruvate kinase (PK) is significantly more phosphorylated than the euthermic control Urocitellus richardsonii

Purification (Commentary)

Purification (Comment) Organism
native enzyme 390fold from skeletal muscle by cation exchange chromatography and affinity chromatography Urocitellus richardsonii

Source Tissue

Source Tissue Comment Organism Textmining
skeletal muscle
-
 Urocitellus richardsonii
-

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
390
-
 purified enzyme, pH 7.0, 37°C Urocitellus richardsonii

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ADP + phosphoenolpyruvate
-
 Urocitellus richardsonii ATP + pyruvate
-
 ?

Subunits

Subunits Comment Organism
? x * 57000, SDS-PAGE Urocitellus richardsonii

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
 assay at Urocitellus richardsonii

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
15.3
-
 ADP purified enzyme, pH 7.0, 5°C Urocitellus richardsonii
15.3
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 5°C Urocitellus richardsonii
56
-
 ADP purified enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii
56
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii
360
-
 ADP purified enzyme, pH 7.0, 35°C Urocitellus richardsonii
360
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 35°C Urocitellus richardsonii

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7
-
 assay at Urocitellus richardsonii

IC50 Value

IC50 Value IC50 Value Maximum Comment Organism Inhibitor Structure
130
-
 torpid enzyme, pH 7.0, 35°C Urocitellus richardsonii guanidine hydrochloride
350
-
 torpid enzyme, pH 7.0, 5°C Urocitellus richardsonii guanidine hydrochloride
376
-
 euthermic enzyme, pH 7.0, 5°C Urocitellus richardsonii guanidine hydrochloride
443
-
 euthermic enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii guanidine hydrochloride
550
-
 torpid enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii guanidine hydrochloride
600
-
 torpid enzyme, pH 7.0, 35°C Urocitellus richardsonii Urea
900
-
 euthermic enzyme, pH 7.0, 5°C Urocitellus richardsonii Urea
1190
-
 torpid enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii Urea
1260
-
 euthermic enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii Urea
1728
-
 torpid enzyme, pH 7.0, 5°C Urocitellus richardsonii Urea

General Information

General Information Comment Organism
malfunction skeletal muscle PK from the Richardson's ground squirrel may be regulated posttranslationally between the euthermic and torpid states, and this may inhibit PK functioning during torpor in accordance with the decrease in glycolytic rate during dormancy Urocitellus richardsonii
metabolism pyruvate kinase (PK) is a key member of the glycolytic pathway. Ground squirrel torpor during winter hibernation is characterized by numerous physiological and biochemical changes, including alterations to fuel metabolism. During torpor, many tissues switch from carbohydrate to lipid catabolism, often by regulating key enzymes within glycolytic and lipolytic pathways Urocitellus richardsonii
physiological function the skeletal muscle pyruvate kinase from the hibernating ground squirrel shows potential regulation by posttranslational modification during torpor. Torpid pyruvate kinase (PK) displays a nearly threefold increase in Km PEP as compared to control PK when assayed at 5°C. Torpid PK is significantly more phosphorylated than the euthermic control. PK from the torpid condition is also shown to possess nearly twofold acetyl content as compared to control PK Urocitellus richardsonii

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
6 12 phosphoenolpyruvate purified enzyme, pH 7.0, 5°C Urocitellus richardsonii
47.8
-
 ADP purified enzyme, pH 7.0, 5°C Urocitellus richardsonii
98.25
-
 ADP purified enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii
818.2
-
 ADP purified enzyme, pH 7.0, 35°C Urocitellus richardsonii
1166.7
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 25°C/room temperature Urocitellus richardsonii
10909.1
-
 phosphoenolpyruvate purified enzyme, pH 7.0, 35°C Urocitellus richardsonii