Kreamer B L, Siegel F L, Gourley G R
Department of PediatricsUniversity of Wisconsin School of Medicine and Waisman Center on Mental Retardation and Human Development, Madison, Wisconsin 53705, USA.
Pediatr Res. 2001 Oct;50(4):460-6. doi: 10.1203/00006450-200110000-00007.
Infants who consume casein hydrolysate formula have been shown to have lower neonatal jaundice levels than infants who consume routine formula or breast milk. Because casein hydrolysate has been shown to contain a beta-glucuronidase inhibitor, one possible mechanism to explain this finding is blockage of the enterohepatic circulation of bilirubin by a component of the formula. The aim of this research was to identify the source of the beta-glucuronidase inhibition in hydrolyzed casein. A beta-glucuronidase inhibition assay and measurements of physical and kinetic parameters were used to analyze the components of hydrolyzed casein and infant formulas. Kinetic studies used purified beta-glucuronidase. The L-aspartic acid in hydrolyzed casein accounts for the majority of the beta-glucuronidase inhibition present. Kinetic studies indicate a competitive inhibition mechanism. L-aspartic acid is a newly identified competitive inhibitor of beta-glucuronidase.
食用酪蛋白水解配方奶粉的婴儿相比食用常规配方奶粉或母乳的婴儿，其新生儿黄疸水平更低。由于已证明酪蛋白水解物含有β-葡萄糖醛酸酶抑制剂，一种可能解释这一发现的机制是该配方奶粉的一种成分阻断了胆红素的肠肝循环。本研究的目的是确定水解酪蛋白中β-葡萄糖醛酸酶抑制作用的来源。采用β-葡萄糖醛酸酶抑制试验以及物理和动力学参数测量来分析水解酪蛋白和婴儿配方奶粉的成分。动力学研究使用纯化的β-葡萄糖醛酸酶。水解酪蛋白中的L-天冬氨酸是β-葡萄糖醛酸酶抑制作用的主要原因。动力学研究表明这是一种竞争性抑制机制。L-天冬氨酸是一种新发现的β-葡萄糖醛酸酶竞争性抑制剂。
