4-Methyleneglutamine synthetase: A new amide synthetase present in germinating peanuts
作者:Harry C. Winter、Ti-Zhi Su、Eugene E. Dekker
DOI:10.1016/0006-291x(83)90332-7
日期:1983.3
catalyzes the synthesis of 4-methyleneglutamine from 4-methyleneglutamic acid + ammonia was detected in and partially purified from cotyledons of peanut seeds germinated 5 to 7 days. This activity was separated from glutamine and asparagine synthetases by ammonium sulfate precipitation and DEAE-cellulose chromatography. The enzyme is distinct from these other amide synthetases in its substrate specificity
在发芽5至7天的花生种子的子叶中并部分纯化了催化从4-亚甲基谷氨酸+氨合成4-亚甲基谷氨酰胺的酶活性。通过硫酸铵沉淀和DEAE-纤维素色谱法将该活性与谷氨酰胺和天冬酰胺合成酶分离。该酶的底物特异性,酰胺/羟胺交换不足,使用铵离子作为酰胺供体以及由ATP形成AMP与这些其他酰胺合成酶不同。该活性在溶液中非常不稳定,但是以沉淀形式保留在硫酸铵中或在-77℃下冷冻在12.5%甘油中时保留。此活性可能是催化发芽花生中发生的4-亚甲基谷氨酰胺快速合成的原因。