标题：A genetic defect in the biosynthesis of dermatan sulfate proteoglycan: galactosyltransferase I deficiency in fibroblasts from a patient with a progeroid syndrome.
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：4
页码：1342-1346
DOI：10.1073/pnas.87.4.1342
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A small proteoglycan that contains only a single dermatan sulfate chain is the main proteoglycan synthesized by skin fibroblasts. Fibroblasts from a patient with progeroidal appearance and symptoms of the Ehlers-Danlos syndrome have a reduced ability of converting the core protein of this proteoglycan into a mature glycosaminoglycan chain-bearing species. This abnormality is the consequence of a deficiency in galactosyltransferase I (xylosylprotein 4-beta-galactosyltransferase; EC 2.4.1.133 ), which catalyzes the second glycosyl transfer reaction in the assembly of the dermatan sulfate chain. The glycosaminoglycan-free core protein secreted by the patient's fibroblasts bears an unsubstituted xylose residue. The mutant enzyme is abnormally thermolabile. Preincubation of fibroblasts at 41 degrees C leads to a further reduction in the production of mature proteoglycan and affects the capacity for glycosaminoglycan synthesis on p-nitrophenyl beta-D-xyloside more strongly in the mutant than in control cells.
