RESUMO
On the basis of o-acylamino-4-methylumbelliferon, a number of beta-galactosides and beta-glucosides have been synthesized. The fluorogenic compounds obtained differ by the length of acyl residues. 6- and 8-hexadecanoylamino-4-methylumbelliferyl-beta-D-galactopyranosides (6-HMGal and 8-HMGal) are shown to be substrates for human galactocerebroside-beta-D-galactosidase. 6-HMGal analogues with shorter acyl residues, octanoyl (OMGal) and butanoyl (BMGal), were cleaved by another type of beta-galactosidase, GM1-ganglioside-beta-galactosidase. It has been established that 6-hexadecanoylamino-4-methylumbelliferyl-beta-D-glucopyranoside (HMGlc) is cleaved by human and animal glucocerebrosidase much slower than its chromogenic analogue (HMGlc). OMGlc did not exceed HNGlc either, though it is cleaved by glucocerebrosidase faster than HMGlc.
Assuntos
Corantes Fluorescentes , Galactosidases/análise , Galactosilceramidase/análise , Glucosidases/análise , Glucosilceramidase/análise , Lisossomos/enzimologia , beta-Galactosidase/análise , Catálise , Fenômenos Químicos , Química , Cromatografia em Gel , Ensaios Enzimáticos Clínicos , Galactosídeos , Galactosilceramidase/deficiência , Glucosídeos , Glucosilceramidase/deficiência , Humanos , Cinética , Esfingolipidoses/diagnóstico , Especificidade por Substrato , beta-Galactosidase/deficiênciaAssuntos
Doença de Fabry/diagnóstico , Ensaios Enzimáticos Clínicos , Diagnóstico Diferencial , Galactosilceramidase/sangue , Galactosilgalactosilglucosilceramidase/sangue , Hexosaminidases/sangue , Humanos , Leucócitos/enzimologia , Lisossomos/enzimologia , Masculino , Pessoa de Meia-Idade , alfa-L-Fucosidase/sangue , beta-Galactosidase/sangueRESUMO
A new fluorogenic compound--6-hexadecanoylamino-4-methyl-umbelliferyl-beta-D-gala cto pyranoside (HMGal), a substrate for human galactocerebroside beta-D-galactosidase (HG), has been synthesized. A method for determining the HG activity based on the use of HMGal as a fluorogenic substrate has been developed. The specificity of HMGal hydrolysis by HG has been demonstrated in experiments with enzyme preparations from human skin fibroblasts and leukocytes in normally and in hereditary glycolipidosis (GM1-gangliosidosis and Krabbe's disease). The use of HMGal permits to markedly increase the sensitivity of the method used for determining the HG activity.
Assuntos
Compostos Cromogênicos/síntese química , Ensaios Enzimáticos Clínicos , Galactosidases/análise , Galactosilceramidase/análise , Gangliosidoses/diagnóstico , Leucodistrofia de Células Globoides/diagnóstico , Fenômenos Químicos , Química , Gangliosídeo G(M1) , HumanosRESUMO
By the autoradiography, the increase of the mean rate of replication fork movement in DNA was shown for human skin fibroblasts during S-period induced by reseeding the stationary culture; the portion of high-rate replicons growing parallel to the increase in numbers of cells, in which the constitutive heterochromatin was replicating. Furthermore, the heterogeneity of replicons was investigated in regard to the rate of DNA chain growth in asynchronous cell populations of human and three rodent species (Microtus agrestis, Tscherskia triton, Cricetulus griseus). A positive correlation was found between the portion of replicons, with a relatively high rate of replication (more than 60 micron/h), and the relative amounts of C-heterochromatin in genomes of these species. On the basis of these studies it has been assumed, that the replicons with the high rate of DNA chain growth belong to the constitutive heterochromatin.