Synthesis Studies On The Process Of Enzymatic Catalysis Of Guanosine Phosphorylation

Disodium 5’-ribonucleotide(I+G) containing disodium 5’-guanylate(5’-GMP) and disodium 5’-Inosinate(5’-IMP) has been widely used in food industry. Phosphotransferase catalysis guanosine phosphorylation received extensive attention of science and technology workers because of its mild reaction conditions, environmental friendly, enzyme specificity, security and environmental protection. This topic researched various factors in the process of phosphotransferase catalytic guanosine phosphorylation in order to establish phosphotransferase catalytic synthesis of disodium 5 ’- guanylic acid reaction system. Besides, we added the coagulant to solve gel phenomenon in the reaction process and improved the concentration of substrate. It laid a foundation to achieve industrialized production of 5 ’- guanosine monophosphate disodium.This paper examined various factors in the process of phosphotransferase catalytic guanosine phosphorylation such as pH value, temperature, time, phosphate, electrolyte gentle infusion of whole-cell. The results show that when the temperature was within the range of 30℃ to 40℃, the activity of enzyme is highest in the pH = 5.2. Andwhen temperature is 30℃ and the pH value is 5.2, after 5 ’- guanosine monophosphate disodium accumulate 3 h, it would began to degradation. Inorganic electrolytes would inhibit this enzyme. And sodium acetate is not obvious about nhibitory effect, but it would inhibited the decomposition of 5 ’- guanosine monophosphate disodium.This paper also studied the influence factors of the gel phenomenon in the reaction process. The results showed that the organic solvent would inhibit this reaction, when we added acetamide, it would inhibit lightly and it would inhibit gel formation obviously. We found both RJ and LP kinds of quaternary ammonium salt compounds can inhibit gel formation, and they have good inhibition for the degradation reaction of 5 ’- guanosine monophosphate disodium. When the reaction added RJ, the conversion rate would reach 90%.This paper discussed effects of the stability of the reaction solution. The results show that when temperature was within the range of 5 ℃ to 65 ℃ and the pH value is 8.0, the reaction solution would optimal stability. It would suitable for post-processing in this condition. After isolated, the chromatographic purity of 5 ’-GMP is more than 98%. And its structure identified by the nuclear magnetic resonance and infrared spectrum. Its quality inspection conforms to the food additive 5’- GMP industry standard QBT 2846-2007.