Identification of the origin of urinary peptides and the assessment of protein nutrition as its application

尿肽来源鉴定及其应用的蛋白质营养评估

• 批准号: 14560110
• 负责人: NOGUCHI Tadashi
• 金额: $ 1.86万
• 依托单位: Chubu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14560110/
• 关键词: Urinary peptide; protein nutrition; nutritional evaluation; Protein degradation; peptide analysis; タンパク質分解; キャピラリー電気泳動

Human urine contains a significant amount of peptides. It has been proved by the present author and his coworkers that the rate of body protein degradation or total turnover rate of body proteins is estimated by determining the rate of this peptide excretion. If the origin of some specific peptides are elucidated and the methods to determine them are developed, they will give very useful information to know the activity, of the original tissues or organs. For example, if some cancer cells excrete some specific peptides, their excretion rate will show the activity of the cancer cells. In order to determine the rate of excretion of some specific peptides, the present author tried to differentiate the peptides by capillary electrophoresis (CE). At first, urinary peptides were differentiated by CE employing phosphate-borate buffer system or formate-ammoinium buffer system. The results showed an excellent fractionation of urinary peptides. There was no clear differentiation between men and women's urine. This confirms that the urinary peptides reflect basic metabolic activity of humans. Employing rats, the effect of dietary cadmium on 'finger print' of urinary peptides were investigated. Dietary cadmium affected the 'fingerprint' of urinary peptides suggesting that the method to elucidate the metabolic status by urinary peptide excretion is valid.

人尿中含有大量的肽。本文作者及其同事已证明，通过测定这种肽的排泄率，可以估计机体蛋白质的降解率或机体蛋白质的总周转率。如果某些特定肽的来源得以阐明，并建立起测定它们的方法，它们将为了解原始组织或器官的活性提供非常有用的信息。例如，如果某些癌细胞分泌某些特定的肽，它们的排泄率将显示癌细胞的活性。为了测定某些特定肽的排泄率，作者尝试用毛细管电泳（CE）来区分这些肽。首先采用磷酸盐-硼酸盐缓冲体系和甲酸盐-铵缓冲体系对尿肽进行电泳鉴别。结果表明，尿肽的分级分离效果良好。男性和女性的尿液之间没有明显的区别。这证实了尿肽反映了人类的基本代谢活动。以大鼠为研究对象，研究了膳食镉对尿肽“指纹”的影响。膳食镉影响了尿肽的“指纹”，提示通过尿肽排泄来阐明代谢状态的方法是有效的。