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Thermodynamic determination of β‐hexosaminidase isoenzymes in mononuclear and polymorphonuclear leukocyte populations
Author(s) -
Casal J. Antonio,
Chabás Amparo,
Tutor J. Carlos
Publication year - 2002
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.10891
Subject(s) - thermolabile , hexosaminidase , isozyme , chemistry , heterozygote advantage , microbiology and biotechnology , beta (programming language) , biochemistry , immunology , enzyme , biology , gene , allele , computer science , programming language
Isoenzymes of β‐hexosaminidase (Hex) were determined in mononuclear (MN) and polymorphonuclear (PMN) leukocytes, with a thermodynamic method using the chromogenic substrate sodio‐3,3′‐dichlorophenolsulfonphthaleinyl N‐acetyl‐β‐D‐glucosaminide. Imprecision was very satisfactory, and the results are very much in agreement with those obtained using the fluorogenic substrates 4‐methylumbelliferyl N‐acetyl‐β‐D‐glucosaminide and 4‐methylumbelliferyl N‐acetyl‐β‐D‐glucosaminide 6‐sulfate. In 163 healthy individuals we found, for the proportion as a percentage of the Hex A isoenzyme, significantly higher values ( P < 0.001) in PMN than in MN cells (71.56 ± 0.30% vs. 54.28 ± 0.24%), meaning that it would not appear advisable to use total leukocyte lysates for evaluating this variable. The method is fast, precise, and highly suitable for the biochemical diagnosis and heterozygote screening of GM2 gangliosidoses, and would be applicable in cases of thermolabile Hex B and for detecting the B1 variant. © 2002 Wiley‐Liss, Inc.