Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving oxidoreductase
Patent
1999-06-08
2000-04-04
Leary, Louise N.
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving oxidoreductase
435 25, 435 14, 435 4, 526 41, 526 11, 526 2624, C12Q 132, C12Q 126, C12Q 154
Patent
active
060460180
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to high sensitive assay method of chiroinositol and a composition for assay thereof in fields of clinical biochemistry and food inspection. More particularly, this invention relates to an assay method of chiroinositol which comprises reacting a specimen containing chiroinositol with substrate of chiroinositol in the presence of a coenzyme selected from nicotinamide adenine dinucleotides (phosphate) [hereinafter designates as NAD(P)s] and a coenzyme selected from thio-nicotinamide adenine dinucleotides (phosphate) [hereinafter designates as thio-NAD(P)s ] ##STR2## wherein a product is a compound, from which 2 or 4 hydrogen atoms are deleted from chiroinositol, A1 is NAD(P)s or thio-NAD(P)s, A2 is a reduced form of A1, B1 is a reduced form of NAD(P)s in case of A1 being thio-NAD(P)s or a reduced form of thio-NAD(P)s in case of A1 being NAD(P)s and B2 is an oxidized form of B1, and determining an amount of converting A2 or B1 by the said reaction. The present invention further relates to a composition for assay of chiroinositol comprising consisting of following components 1)-3); substrate of chiroinositol in the presence of a coenzyme selected from NAD(P)s and a coenzyme selected from thio-NAD(P)s, in case of at least a coenzyme selected from NAD(P)s, or in the above 2), at least a coenzyme selected from reduced NAD(P)s in case of at least ,t coenzyme selected from thio-NAD(P)s.
PRIOR ARTS
In recent years, since an importance in insulin resistance has been recognized as a cause of glucose tolerance failure including diabetes mellitus, especially diabetes mellitus type II, or as a risk factor for arteriosclerosis, some of assay methods for insulin resistance have developed. However, idealistic assay methods with highly accuracy, simple and low price have never been known.
Involvement of chiroinositol in insulin signal has reported and is thought to be an index for insulin resistance. [Larner J. et al., New Eng. J. Med., 323, 373-378 (1990), Published Japanese translation of PCT international publication for patent application (hereinafter designates as JPCT) No. 4-504001 (WO90/10711) and JPCT No. 4-505218 (WO91/12335A)]. The above JPCT No. 4-504001 and JPCT No. 4-505218 disclose that assay of chiroinositol in body fluid such as blood or urine for diagonosis of diabetes mellitus, especially insulin resistance, is useful, and suggest reduction/oxidation analysis using enzyme, however no concrete method has proposed.
Chiroinositol measured by GC-mass spectrum analysis has been reported. [Toshimitsu Niwa, J. Chromatography, 227 (1983), 25-39, ibid, 336 (1984), 345-350]. These methods require, however, pretreatment with complex operation and difficult to treat for many specimens as well as require expensive equipment, which cause high costs.
In Japanese Unexamined Patent Publication No. 8-21835, immunoassay using specific antibody for chiroinositol is disclosed for solving these problems. There may be problems, however, in the immunochemical assay with highly sensitive in one hand and with less reproducibility, effective for treatment of specimens in a unit time and cost effectiveness as compared with biochemical assay method using enzyme in the other hand.
For supplying accurate, simple and low cost assay method for chiroinositol, enzymatic method may be one of the most preferable methods. However, there is no clear-cut report on an enzyme which catalyses a reaction with chiroinositol. Especially, no report is known on an enzyme which catalyses a reaction with chiroinositol using thio-NAD(P)s as coenzymes.
Myoinositol dehydrogenase produced by Aerobacter aerogenes has been reported to have very weak activity for chiroinositol in its substrate specificity using a coenzyme NAD as compared with myoinositol (Biochim. Biophys. Acta 17, 608, 1958). Consequently, such the enzyme may not be preferable for assay of chiroinositol, which is observed trace level in vivo. Commercially available myoinositol dehydrogenase (originated from Aerobacter aerogenes, SIGMA Inc. I-0255)
REFERENCES:
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patent: 5356790 (1994-10-01), Ueda et al.
A. Kennington et al., "Low Urinary chiro-Inositol Excretion in Non-Insulin-Dependent Diabetes Mellitus", The New England Journal of Medicine, vol. 323, No. 6, 1990, pp. 373-378.
T. Niwa et al., "Gas Chromatographic-Mass Spectrometric Analysis of Polyols in Urine and Serum of Uremic Patients", Journal of Chromatography, vol. 277, 1983, pp. 25-39.
T. Niwa et al., "Identification of 6-deoxyallitol and 6-deoxygulitol in human urine Electron-impact mass spectra of eight isomers of 6-deoxyhexitol", Journal of Chromatography, vol. 336, 1984, pp. 345-350.
A. Weissbach, The Enzymic Determination of Myo-Inositol, Biochimica et Biophysica Acta, vol. 27, 1958, pp. 608-611.
P. Sneath, "Endospore-forming Gram-Positive Rods and Cocci",Bergery's Manual of Systematic Bacteriology, vol. 2, pp. 1104-1139.
M. Vidal-Leiria et al., "Inositol Dehydrogenase from the Yeast Cryptococcus Melibiosum", Biochimica et Biophysica Acta, vol. 293, 1973, pp. 295-303.
T. Berman et al., The Pathway of myo-Inositol Degradation in Aerobacter Aerogenes, The Journal of Biological Chemistry, vol. 241, No. 4, 1966, pp. 800-806.
Kozuma Takuji
Takahashi Mamoru
Asahi Kasei Kogyo Kabushiki Kaisha
Leary Louise N.
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