Human plasma protein Z antigen: range in normal subjects and effect of warfarin therapy.
Human plasma protein Z antigen: range in normal subjects and effect of warfarin therapy.
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DOI：
10.1182/blood.v69.6.1580.bloodjournal6961580
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发表时间：
1987
期刊：
影响因子：
20.3
通讯作者：
J. Miletich;G. Broze
中科院分区：
文献类型：
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作者：
J. Miletich;G. Broze
与其他在血浆中循环的维生素k依赖性蛋白相比，蛋白Z抗原的变化要大得多。455例正常健康供者血浆EDTA浓度呈正态分布，平均值为2.9微克/毫升（46 nmol/L），标准差为1.0微克/毫升（95%区间为平均值的32% ~ 168%）。未发现与年龄或性别有显著相关性。相比之下，在相同的455份样品上，用同一种方法测得的蛋白C抗原浓度呈对数正态分布，平均值为4.0微克/毫升（65 nmol/L）， 95%区间为平均值的70% ~ 138%。与其他血浆维生素k依赖性蛋白相比，接受稳定华法林治疗的患者的总蛋白Z抗原水平极低（范围为正常人的1%至16%）。此外，尽管正常血浆中95%以上的抗原被柠檬酸钡吸附（这是γ -羧谷氨酸（Gla）残基存在的粗略反映），但在服用华法林的患者中，几乎所有的少量抗原都未能被吸附，这表明实际上没有蛋白Z具有完整的Gla残基补体。同样25例患者的总蛋白C抗原平均为正常人的53%(34% ~ 72%)，总剩余抗原中仍有54%（平均）吸附在柠檬酸钡上。给华法林负荷剂量的正常人血浆中蛋白Z抗原的浓度以每天约20%的初始速率下降，表明血浆半衰期（t1/2）为2至3天。
In contrast to the other well-studied vitamin K-dependent proteins that circulate in plasma, protein Z antigen is much more variable. The concentration in plasmas collected in EDTA from 455 normal, healthy donors is normally distributed with a mean of 2.9 micrograms/mL (46 nmol/L) and a SD of 1.0 microgram/mL (95% interval of 32% to 168% of the mean). No significant correlation to age or sex could be detected. In comparison, the concentration of protein C antigen measured with the same type of assay on the same 455 samples has a log normal distribution with a mean of 4.0 micrograms/mL (65 nmol/L) and a 95% interval of 70% to 138% of the mean. Also in marked contrast to other plasma vitamin K-dependent proteins, the total protein Z antigen level is extremely low in patients on stable warfarin therapy (range 1% to 16% of normal). Moreover, even though greater than 95% of the antigen in normal plasmas adsorbs to barium citrate (a crude reflection of the presence of gamma-carboxyglutamic acid (Gla) residues), in the patients taking warfarin almost all of the small amount of the antigen failed to adsorb, suggesting that virtually no protein Z had its full complement of Gla residues. Total protein C antigen in the same 25 patients averaged 53% of normal (34% to 72%) and 54% (average) of the total remaining antigen still adsorbed to barium citrate. The concentration of protein Z antigen in the plasma of a normal individual given a loading dose of warfarin fell at an initial rate of approximately 20% a day, indicating a plasma half-life (t1/2) of 2 to 3 days.