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Galactose metabolism in transferase‐deficient galactosaemic and normal long‐term lymphoid cell lines
Author(s) -
Beratis N. G.,
Wilbur L.
Publication year - 1987
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/bf01799977
Subject(s) - galactose , cell culture , transferase , galactosemia , metabolism , biochemistry , cell , biology , enzyme , microbiology and biotechnology , chemistry , endocrinology , medicine , genetics
Summary The activity (mean±SD) of galactose‐1‐phosphate uridyl transferase in two long‐term lymphoid cell lines from Caucasian patients with transferase deficiency galactosaemia, a heterozygote, and eight normal subjects was 0, 78 and 168±55 nmol UDPG consumed (mg protein) −1 h −1 , respectively. Also, no activity was found in erythrocytes and cultured fibroblasts from the patients. A small number of cells of the galactosaemic lines cultured in medium, in which galactose was substituted for glucose, survived for 37 days. Normal and galactosaemic lines incubated with D ‐galactose‐[1‐ 14 C] liberated 218.2±65.6 and 18.1 pmol 14 CO 2 (mg cellular protein) −1 (6h) −1 , respectively. The evolution of 14 CO 2 from D ‐glucose‐[1‐ 14 C] was similar in normal and galactosaemic lines. In the presence of [ 3 H] galactose the radioactivity incorporated into TCA‐precipitated material of the galactosaemic lines was 6.8% of the normal lines. Approximately 26% and 1.3% of the total radioactivity was incorporated into molecular species with a molecular weight greater than 4 daltons in normal and galactosaemic cells, respectively. Similar molecules were identified in the cell‐free medium of both normal and deficient cells except for an 18000 daltons molecule identified only in the medium of the normal cells. These findings indicate that a small amount of galactose is metabolized in galactosaemic lines with no transferase activity.