RESUMO
Cyclodextrin glucanotransferase, the essential enzyme for the production of cyclodextrins, has become the focus of scientific research nowadays. Although many related enzyme properties are well known, the crucial factors in product specificity determination remain to be answered. Here, the recent research progresses of cyclodextrin glucanotransferase, especially those about the evolution of product specificity, were reviewed, and the scientific problems were discussed.
Assuntos
Proteínas Arqueais , Genética , Metabolismo , Bacillus , Genética , Proteínas de Bactérias , Genética , Metabolismo , Biocatálise , Ciclodextrinas , Metabolismo , Evolução Molecular , Glucosiltransferases , Classificação , Genética , Metabolismo , Mutação , Thermoanaerobacterium , Genética , ThermococcusRESUMO
<p><b>OBJECTIVE</b>To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA).</p><p><b>METHODS</b>The amount of (3)H-TdR ((3)H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA) content of the VSMC were assayed.</p><p><b>RESULTS</b>1x10(-9), 1x10(-8), 1x10(-7) mol/L LPA in a concentration dependent manner, induced the amount of (3)H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%, and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of (3)H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01) respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1x10(-7) mol/L LPA-treated VSMC.</p><p><b>CONCLUSIONS</b>LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion.</p>