Coon C N, Sowers A, Couch J R
Poult Sci. 1975 Sep;54(5):1461-7. doi: 10.3382/ps.0541461.
The effect of feeding low protein diets with and without 2% glycine or 2% L-serine to chicks upon the enzymes concerned in the matabolism of glycine and serine has been determined. D-3-phosphoglycerate dehydrogenase (EC 1.1.1.s), hosphoserine phosphatase (EC 3.1.3.3), and serine hydroxymethyltransferase (EC 2.1.2.1) activities were significantly increased in livers from chicks fed 75% protein diets as compared to liver enzyme activities from chicks fed either 24% chick starter, 2% or 25% protein diets. Phosphoserine phosphatase activity was significantly higher in kidney tissue of chicks fed 75% protein diets. Livers from chicks fed 25% protein diets had a higher activity for D-3-phosphoglycerate dehydrogenase and phosphoserine phosphatase than did those fed chick starter or 2% protein diets. D-3-phosphoglycerate dehydrogenase and phosphoserine phosphatase activities were higher in livers from chicks fed 2% protein, 2% protein + 2% glycine, and 2% protein + 2% L-serine diets when compared to those from chicks fed low protein diets with supplemental methionine or cysteine. Serine dehydratase (EC 4.2.1.13), glycerate dehydrogenase (EC 1.1.1.29) and hydroxypyruvate-P: L-glutamate transaminase activities remained constant in livers from chicks fed all experimental diets. The uric acid concentration was significantly increased in plasma from chicks fed the high protein diets which suggests that D-3-phosphoglycerate dehydrogenase, phosphoserine phosphatase and serine hydroxymethyltransferase activities were increased because of the high requirement for glycine in uric acid formation. The 75% protein diet provided three times as much glycine as the 25% protein diet which may have met the increased need for glycine for uric acid formation.
已测定给雏鸡饲喂含或不含2%甘氨酸或2% L-丝氨酸的低蛋白日粮对甘氨酸和丝氨酸代谢相关酶的影响。与饲喂24%雏鸡开食料、2%或25%蛋白日粮的雏鸡肝脏酶活性相比，饲喂75%蛋白日粮的雏鸡肝脏中D-3-磷酸甘油酸脱氢酶（EC 1.1.1.s）、磷酸丝氨酸磷酸酶（EC 3.1.3.3）和丝氨酸羟甲基转移酶（EC 2.1.2.1）的活性显著增加。饲喂75%蛋白日粮的雏鸡肾脏组织中磷酸丝氨酸磷酸酶活性显著更高。饲喂25%蛋白日粮的雏鸡肝脏中D-3-磷酸甘油酸脱氢酶和磷酸丝氨酸磷酸酶的活性高于饲喂雏鸡开食料或2%蛋白日粮的雏鸡。与饲喂添加蛋氨酸或半胱氨酸的低蛋白日粮的雏鸡相比，饲喂2%蛋白、2%蛋白 + 2%甘氨酸和2%蛋白 + 2% L-丝氨酸日粮的雏鸡肝脏中D-3-磷酸甘油酸脱氢酶和磷酸丝氨酸磷酸酶的活性更高。在饲喂所有实验日粮的雏鸡肝脏中，丝氨酸脱水酶（EC 4.2.1.13）、甘油酸脱氢酶（EC 1.1.1.29）和羟基丙酮酸-P：L-谷氨酸转氨酶的活性保持恒定。饲喂高蛋白日粮的雏鸡血浆中尿酸浓度显著增加，这表明D-3-磷酸甘油酸脱氢酶、磷酸丝氨酸磷酸酶和丝氨酸羟甲基转移酶的活性增加是由于尿酸形成过程中对甘氨酸的高需求。75%蛋白日粮提供的甘氨酸是25%蛋白日粮的三倍，这可能满足了尿酸形成对甘氨酸增加的需求。
