• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>American Journal of Physiology >Protein kinetics determined in vivo with a multiple-tracer, single-sample protocol: application to lactase synthesis.
【24h】

Protein kinetics determined in vivo with a multiple-tracer, single-sample protocol: application to lactase synthesis.

机译：用多示踪剂，单样品方案在体内测定蛋白质动力学：应用于乳糖酶合成。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Precise analysis of the kinetics of protein/enzyme turnover in vivo has been hampered by the need to obtain multiple tissue samples at different times during the course of a continuous tracer infusion. We hypothesized that the problem could be overcome by using an overlapping (i.e., staggered) infusion of multiple stable amino acid isotopomers, which would take the place of multiple tissue samples. We have measured, in pigs, the in vivo synthesis rates of precursor (rapidly turning over) and mature (slowly turning over) polypeptides of lactase phlorizin hydrolase (LPH), a model for glycoprotein synthesis, by using an overlapping infusion of [2H3]leucine, [13C1]leucine, [13C1]phenylalanine, [2H5]phenylalanine, [13C6]phenylalanine, and [2H8]phenylalanine. Blood samples were collected at timed intervals, and the small intestine was collected at the end of the infusion. The tracer-to-tracee ratios of each isotopomer were measured in the plasma and jejunal free amino acid pools as well as in purified LPH polypeptides. These values were used to estimate kinetic parameters in vivo using a linear steady-state compartmental model. The fractional synthesis rates of the high-mannose, complex glycosylated and mature brush-border LPH polypeptides, so determined, were 3.3 +/- 1.1%/min, 17.4 +/- 11%/min, and 0.089 +/- 0.02%/min, respectively. We conclude that this multiple-tracer, single-sample protocol is a practicable approach to the in vivo measurement of protein fractional synthesis rates when only a single tissue sample can be obtained. This method has broad application and should be particularly useful for studies in humans.
机译：由于需要在连续的示踪剂输注过程中的不同时间获取多个组织样本，因此妨碍了体内蛋白质/酶转换动力学的精确分析。我们假设可以通过重叠（即交错）输注多种稳定的氨基酸异位异构体来解决该问题，该替代将取代多个组织样本。我们已经通过重复输注[2H3]来测量猪中乳糖酶Phrizrizin水解酶（LPH）的前体（快速翻转）和成熟（缓慢翻转）多肽的体内合成速率，这是糖蛋白合成的模型。亮氨酸，[13C1]亮氨酸，[13C1]苯丙氨酸，[2H5]苯丙氨酸，[13C6]苯丙氨酸和[2H8]苯丙氨酸。定时采集血样，并在输液结束时采集小肠。在血浆和空肠游离氨基酸库以及纯化的LPH多肽中测量每种同功异构体的示踪比。这些值用于使用线性稳态区室模型估算体内动力学参数。如此确定的高甘露糖，复杂糖基化和成熟的刷式边界LPH多肽的分数合成率为3.3 +/- 1.1％/ min，17.4 +/- 11％/ min和0.089 +/- 0.02％/分钟，分别。我们得出的结论是，当只能获得单个组织样品时，这种多示踪剂，单样品方案是一种用于体内测量蛋白质分数合成速率的实用方法。该方法具有广泛的应用，对人体研究特别有用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号