کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3368568 1218801 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Coeliac autoantibodies can enhance transamidating and inhibit GTPase activity of tissue transglutaminase: Dependence on reaction environment and enzyme fitness
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی
پیش نمایش صفحه اول مقاله
Coeliac autoantibodies can enhance transamidating and inhibit GTPase activity of tissue transglutaminase: Dependence on reaction environment and enzyme fitness
چکیده انگلیسی

Modification of the enzymatic functions of tissue transglutaminase (TG2) by anti-TG2 autoantibodies may play a role in manifestations of coeliac disease. Our aim was to evaluate the effect of coeliac autoantibodies on reactions catalysed by TG2 by a systematic biochemical approach, and in relation to observed clinical presentation type. Coeliac antibodies did not have significant inhibitory effect on transamidation/deamidation activity of TG2 as measured by amine-incorporation into solid and immobilised casein and by ultraviolet kinetic assay. In contrast, immunoglobulins from patients with severe malabsorption enhanced the reaction velocity to 105.4–242.2%. This activating effect was dose-dependent, most pronounced with immobilised glutamine-acceptor substrates, and correlated inversely with the basal specific activity of the enzyme and with dietary treatment. A similar activation could be demonstrated also with the TG2-specific fraction of autoantibodies and in transamidation activity assays which use fibronectin-bound TG2 and thereby mimic in vivo conditions. These results suggest that coeliac antibodies may stabilise the enzyme in a catalytically advantageous conformation. GTPase activity of TG2 decreased to 67.0–73.4% in the presence of antibodies raising the possibility that inhibition of GTPase activity may affect cellular signalling in case coeliac autoantibodies would reach intracellular compartments.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Autoimmunity - Volume 26, Issue 4, June 2006, Pages 278–287
نویسندگان
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