Thermodynamic Determination of Plasma and Leukocyte beta-Hexosaminidase Isoenzymes in Homozygote and Heterozygote Carriers for the GM2 Gangliosidosis B1 Variant

Casal, J.; Pérez, Luis Francisco; Tutor, J. Carlos

doi:10.1309/ahtklprkb4nw0x5m

Cited by 4 publications

(4 citation statements)

References 14 publications

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“…In fact, Casal et al (2003a) reported that the use of different Ea values (i.e., 41.8 and 75.1 kJ/mol) of β-hexosamidase isoenzymes was successful for performing diagnosis and heterozygote screening of GM2 gangliosidoses. Similar approach was applied to determine the B1 variant of Hex in mononuclear and polymorphonuclear leukocyte populations (Casal et al, 2003b). In addition, seasonal variations of lactate dehydrogenases (LDH) from white muscle and liver of Norwegian coastal cod for thermal acclimation was determined by measurements of Ea changes for pooled LDH isozymes from each tissue (Zakhartsev et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Application of mixture rule to determine arrhenius activation energy of time temperature integrator using mixture of laccase from Pleurotus ostreatus and PEGylated laccase from Trametes versicolor

Kim

Choi

Yoon

et al. 2013

J Korean Soc Appl Biol Chem

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Two isoenzyme mixture system was developed to freely adjust the Arrhenius activation energy (Ea), which is one of the most important parameters to design a reliable time temperature integrators (TTIs). We hypothesized that the apparent Ea of a mixture of two isozymes would be expressed in a simple linear relationship with the ratio of the mixture, although it could be expressed with a rather complicate equation. To prove our hypothesis, laccase from Pleurotus ostreatus (Ea =27.06 kJ/mol) and PEGylated laccase from Trametes versicolor (Ea =50.35 kJ/ mol) were used to prepare enzyme mixtures with ratios of 0, 0.25, 0.5, 0.75, and 1.0. The enzyme activity was determined by the increase of absorbance of 2,2'-azino-bis(3-ethylbenzothiazoline-6sulphonic acid) incubated at 5−30 o C, pH 5.0, and Ea for each enzyme mixture was determined to be in the range of 27.06−50.35 kJ/mol. Relationship between Ea and a ratio of the enzyme mixture not only turned out to be linear, but also was well fitted to the linear mixture rule. This newly found linear dependency is much simpler than kinetically derived one, presumably because microscopic reaction paths and thermodynamic parameters were combined and cancelled out, resulting in linearity. This finding is important in that a mixture of two enzymes with a proper ratio determined from the simple linear mixture rule can customize Ea of an enzymatic TTI. This easier and convenient method can offer a practical and reliable way to adjust Ea of an enzymatic TTI on demand.

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Section: Introductionmentioning

confidence: 99%

Application of mixture rule to determine arrhenius activation energy of time temperature integrator using mixture of laccase from Pleurotus ostreatus and PEGylated laccase from Trametes versicolor

Kim

Choi

Yoon

et al. 2013

J Korean Soc Appl Biol Chem

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“…In turn, recently Eirís et al (20) described two Galician non-consanguineous B1 homozygous patients. Likewise, a biochemical diagnosis was made in our laboratory of a patient with GM2 gangliosidosis, the son of a Galician mother who was a heterozygous carrier of the B1 variant, and a father of Jordanian origin who was a heterozygous carrier for the B variant (21). Similarly, 5 non-consanguineous Galician heterozygous B1 variant carriers were identified, with all cases presenting the R178H mutation.…”

Section: Geographic and Ethnic Distribution Of The Gm2 Gangliosidosismentioning

confidence: 99%

“…For some years we have been working on the possible thermodynamic characterization of the enzyme heterogeneity of Hex in different physiopathological situations (21,(23)(24)(25)(26)(27)(28)(29)(30)(31)(32). The enzyme activities are determined at 25º, 30º, 35º and 37ºC with a Cobas Bio analyzer (Roche Diagnostics) using the neutral chromogenic substrate 3,3'-dichlorophenolsulfonphthaleinyl N-acetyl-ß-D-glucosaminide, and the Arrhenius plots and the apparent activation energies are calculated.…”

Section: Biochemical Characterization Of Homozygous and Heterozygous mentioning

confidence: 99%

“…These results made it possible to apply the previously described thermodynamic procedures (23,28) to the study of the enzyme heterogeneity of Hex in different types of biological samples for the biochemical diagnosis of homozygotes and for the detection of heterozygous carriers of the B1 variant (21). The results obtained were highly consistent with those obtained using 4-methylumbelliferyl N-acetyl-ß-D-glucosaminide 6-sulfate as substrate, with isoenzymatic activities and relative proportions of Hex A in mononuclear and polymorphonuclear leukocytes being highly discriminatory, as shown in Figure 1.…”

Section: Biochemical Characterization Of Homozygous and Heterozygous mentioning

confidence: 99%

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Biochemical characterization of the GM2 gangliosidosis B1 variant

Tutor

2004

Braz J Med Biol Res

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The deficiency of the A isoenzyme of ß-hexosaminidase (Hex) produced by different mutations of the gene that codes for the α subunit (Tay-Sachs disease) has two variants with enzymological differences: the B variant consists of the absence of Hex A isoenzyme and the B1 variant produces an inactive Hex A isoenzyme for the hydrolysis of the GM2 ganglioside and synthetic substrates with negative charge. In contrast to the early childhood form of the B variant, the B1 variant appears at a later clinical stage (3 to 7 years of age) with neurodegenerative symptoms leading to the death of the patient in the second decade of life. The most frequent mutation responsible for the GM2 gangliosidosis B1 variant is R178H, which has a widespread geographic and ethnic distribution. The highest incidence has been described in Portugal, which has been suggested as the point of origin of this mutation. Biochemical characterization of this lysosomal disease is carried out using negatively charged synthetic α subunit-specific sulfated substrates, since Hex A isoenzyme heat-inactivation assays are not applicable. However, the determination of the apparent activation energy of Hex using the neutral substrate 3,3'-dichlorophenolsulfonphthaleinyl N-acetyl-ß-D-glucosaminide, may offer a valid alternative. The presence of an α subunit in the αß heterodimer Hex A means that its activation energy (41.8 kJ/mol) is significantly lower than that of the ßß homodimer Hex B (75.1 kJ/mol); however, as mutation inactivates the α subunit, the Hex A of the B1 variant presents an activation energy that is similar to that of the Hex B isoenzyme. Correspondence

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Prenatal Diagnosis of Disorders of Lipid Metabolism

Winchester¹

2009

Genetic Disorders and the Fetus

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Thermodynamic Determination of Plasma and Leukocyte beta-Hexosaminidase Isoenzymes in Homozygote and Heterozygote Carriers for the GM2 Gangliosidosis B1 Variant

Cited by 4 publications

References 14 publications

Application of mixture rule to determine arrhenius activation energy of time temperature integrator using mixture of laccase from Pleurotus ostreatus and PEGylated laccase from Trametes versicolor

Application of mixture rule to determine arrhenius activation energy of time temperature integrator using mixture of laccase from Pleurotus ostreatus and PEGylated laccase from Trametes versicolor

Biochemical characterization of the GM2 gangliosidosis B1 variant

Prenatal Diagnosis of Disorders of Lipid Metabolism

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