HEXOKINASE from Microorganism

Request a quote

Appearance :White amorphous powder, lyophilized
Activity :Grade Ⅲ 150 U/mg-solid or more
Stability :Stable at −20 ℃ for at least one year(Fig.1)
Molecular weight :approx. 82,000 (by gel filtration)
Isoelectric point :4.1±0.1
+

  Share
Guaranteed Safe CheckoutTrust

PREPARATION and SPECIFICATION

AppearanceWhite amorphous powder, lyophilized
ActivityGradeⅢ 150 U/mg-solid or more
ContaminantsPhosphoglucose isomerase≤1.0×10-1 %
6-Phosphogluconate dehydrogenase≤1.0×10-2 %
Glucose-6-phosphate dehydrogenase≤1.0×10-2 %
Myokinase≤1.0×10-2 %
Glutathione reductase≤5.0×10-1%

PROPERTIES

StabilityStable at −20 ℃ for at least one year(Fig.1)
Molecular weightapprox. 82,000 (by gel filtration)
Isoelectric point4.1±0.1
Michaelis constants2.3×10-4 M (D-Glucose), 7.7×10-5 M (ATP)
InhibitorsMetal ions, p-chloromercuribenzoate, iodoacetamide, SDS, etc
Optimum pH8.0−9.0(Fig.2)
Optimum temperature50 ℃(Fig.3)
pH StabilitypH 4.0−9.0 (25 ℃, 20 hr)(Fig.4)
Thermal stabilitybelow 45 ℃ (pH 7.0, 30 min)(Fig.5)
Substrate specificity(Table 1)
Effect of various chemicals(Table 2)

APPLICATIONS

The enzyme is useful for enzymatic determination of glucose, adenosine-5′-triphosphate (ATP) and creatine phosphokinase in combination with glucose-6-phosphate dehydrogenase (=G-6-PDH, G6D311G6D-321).

ASSAY

Principle

Principle

Principle

The formation of NADH is measured at 340 nm by spectrophotometry.

Unit definition

One unit causes the formation of one micromole of NADH per minute under the conditions detailed below.

Method

Reagents

A. Tris-HCl buffer, pH 8.050 mM, containing 13.3 mM MgCl2
B. Glucose solution0.67 M in Tris-HCl buffer solution (A) (The solution should be keep at room temperature for at least 1 hour before use)
C. ATP solution16.5 mM in Tris-HCl buffer solution (A) (Should be freshly prepared)
D. NAD solution6.8 mM in Tris-HCl buffer solution (A) (Should be freshly prepared)
E. G-6-PDH solution300 U/mL (Dilute with Tris-HCl buffer solution (A) and store on ice)
F. Enzyme diluentTris-HCl buffer solution (A) containing 0.1 % of bovine serum albumin

Procedure

1.Prepare the following reaction mixture in a cuvette (d= 1.0cm) and equilibrate at 30℃ for approximately 5 minutes.

2.30 mLTris-HCl buffer solution(A)
0.50 mLGlucose solution(B)
0.10 mLATP solution(C)
0.10 mLNAD solution(D)
0.01 mLG-6-PDH solution(E)
Concentration in assay mixture
Tris-HCl buffer50 mM
Glucose0.11 M
ATP0.53 mM
NAD0.22 mM
MgCl213 mM
BSA3.2 μg/mL
G-6-PDHapprox.1.0 U/mL

2.Add 0.1ml of the enzyme solution* and mix by gentle inversion.

3.Record the increase of optical density at 340 nm against water for 4 to 5 minutes with a spectrophotometer thermostated at 30 ℃ and calculate the ΔOD per minute from the initial portion of the curve (ΔOD test).

At the same time, measure the blank rate (ΔOD blank) by the same method as the test except that the enzyme diluent (F) is added instead of the enzyme solution.

*Dissolve the enzyme preparation on ice-cold enzyme diluent (F) and dilute to 0.1−0.3 U/mL with the same buffer, immediately before the assay.

Calculation

Activity can be calculated by using the following formula :

  • Volume activity (U/ml) =

  • ΔOD/min (OD test−OD blank)×Vt×df


    6.22×1.0×Vs

  • = ΔOD/min×5.0×df

Weight activity (U/mg) = (U/ml)×1/C

Vt: Total volume (3.11 mL)
Vs: Sample volume (0.1 mL)
1.0: Light path length (cm)
6.22: Millimolar extinction coefficient of NADH (cm2/micromole)
df: Dilution factor
C: Enzyme concentration in dissolution (c mg/mL)

Table 1. Substrate specificity of Hexokinase

[Pyruvate kinase-Lactate dehydrogenase system with 0.1 M Tris-HCl buffer, pH 7.5]

  • Substrate(100mM)Relative activity(%)
    D-Glucose100
    D-Fructose140
    D-Mannose52
    2-Deoxy-D-glucose91
  • Substrate(100mM)Relative activity(%)
    D-Galactose0
    D-Xylose2
    D-Glucosamine58

Table 2. Effect of Various Chemicals on Hexokinase

[The enzyme dissolved in 50mM K-phosphate buffer, pH 6.5 (5 U/mL) contg. 0.1 % bovine serum albumin was incubated with each chemical at 30 ℃ for 1hr.]

  • ChemicalConcn.(mM)Residual
    activity(%)
    None100
    Metal salt
    AgNO32.00
    BaCl22.099
    CaCl22.098
    CdCl22.085
    CoCl22.085
    CuSO42.025
    FeCl32.028
    FeSO42.080
    HgCl22.00
    MgCl22.098
    MnCl22.0100
    NiCl22.0100
    Pb(OAc)22.098
    Zn(OAc)22.098
    ZnSO42.099
    NaF20.0101
    NaN320.0102
  • ChemicalConcn.(mM)Residual
    activity(%)
    PCMB2.00
    MIA2.080
    IAA2.07
    EDTA5.0103
    (NH4)2SO420.0104
    Borate20.0102
    o-Phenanthroline2.0101
    α,α′-Dipyridyl2.0102
    Urea2.0104
    Guanidine2.0103
    Hydroxylamine2.0104
    Na-cholate1.0 %102
    Triton X-1001.0 %105
    Brij 351.0 %0
    SDS0.1 %25
    Tween 200.1 %101
    Span 200.1 %106
    DAC0.1 %101

Ac, CH3CO; NEM, N-Ethylmaleimide; PCMB, p-Chloromercuribenzoate; MIA, Monoiodoacetate; EDTA, Ethylenediaminetetraacetate; IAA, Iodoacetamide; SDS, Sodium dodecyl sulfate; DAC, Dimethylbenzylalkylammonium chloride.

  • Fig.1. Stability (Powder form)

    Fig.1. Stability (Powder form)

    (kept under dry conditions)

  • Fig.2. pH-Activity

    Fig.2. pH-Activity

    30 ℃ in the 50 mM buffer solution: pH 6.2-7.5, PIPES-NaOH: pH 7.5-9.0, Tris-HCI: pH 9.0-10.0, Glycine-NaOH

  • Fig.3. Temperature activity

    Fig.3. Temperature activity

    (in 50 mM Tris-HCI buffer,pH 8.0)

  • Fig.4. pH-Stability

    Fig.4. pH-Stability

    25 ℃, 20 hr-treatment in the 0.1 M buffer solution: pH 4.0-8.0,Acetate-NaOH;pH 6.0-8.0, K-phosphate; pH 7.5-9.0,Tris-HCl;pH 9.0-10.5, Glycine-NaOH enzyme concn.: ca.10 U/mL

  • Fig.5. Thermal stability

    Fig.5. Thermal stability

    30 min-treatment with 50 mM K-phosphate buffer, pH 7.0, containing 0.1% bovine serum albumin enzyme concn.: ca.5 U/mL

2. MSDS

3. Tech Data Sheets/Manuals

Size

1 MG, 10 MG, 5 MG

Based on 0 reviews

0.00 Overall
0%
0%
0%
0%
0%
Be the first to review “HEXOKINASE from Microorganism”

Your email address will not be published. Required fields are marked *

Write a review

Reviews

There are no reviews yet.

SKU: A8GD-1009 Category:  Tags: , ,
YOU MAY ALSO LIKE…
My Cart
Close Wishlist
Close Recently Viewed
Categories