Metallothionein: structure/antigenicity and detection/quantitation in normal physiological fluids.
Metallothionein: structure/antigenicity and detection/quantitation in normal physiological fluids.
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DOI：
10.1289/ehp.8454117
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发表时间：
1984-03
影响因子：
10.4
通讯作者：
Garvey JS
中科院分区：
文献类型：
--
作者：
Garvey JS
近年来，放射免疫分析法（RIA）在检测和定量人血清和尿液中金属硫蛋白（MT）方面的应用实验表明，将MT的实际定量下限从以前的50-100 pg扩展到1 pg是可能的。正常血清的RIA表明，MT的典型浓度范围为小于0.01 ng/mL至约1 ng/mL，浓度高于2 ng/mL应视为异常。正常尿液的典型范围为小于1 ng/mL至10 ng/mL;浓度高于10 ng/mL应视为异常。目前正在开发一种补充测定法，即酶联免疫吸附测定法。ELISA是一种竞争性结合测定法，通过比色法或荧光法检测和定量MT。目前用于ELISA中MT定量的有用范围为约50-50000 pg（荧光法）或500-5000 pg（比色法）。最近使用RIA的实验已经鉴定了脊椎动物MT的主要抗原决定簇，其涉及直接氨基末端残基（-MDPNC-）和包括残基20-25的区段（人MT中的-KCKECK-）。基于亲水性和序列分析的二级结构的理论预测表明，构象谱由β转角（反向转角）的四肽候选物主导，其中2-3个六肽序列是螺旋构象的候选物，4-5个短序列（3-5个残基）是β链构象的候选物。螺旋候选人预测是不稳定的，分析有利于逆转脊椎动物MT的决定因素和集群A和B之间的连接区域的隔离位置。
Recent experiments in the application of radioimmunoassay (RIA) in the detection and quantitation of metallothionein (MT) in human sera and urines demonstrate that it is possible to extend the lower limit of practical quantitation from the previous limit of 50-100 pg to 1 pg.RIA of normal sera indicates that the typical range of concentrations of MT is from less than 0.01 ng/mL to about 1 ng/mL, and that concentrations above 2 ng/mL should be considered abnormal. The typical range for normal urines is from less than 1 ng/mL to 10 ng/mL; concentrations above 10 ng/mL should be considered abnormal. A complementary assay, the enzyme-linked immunosorbent assay (ELISA), is under development. The ELISA is a competitive binding assay, detection and quantitation of MT being either by colorimetric or fluorimetric methods. The present useful range for MT quantitation in the ELISA is from about 50-50000 pg (fluorimetric) or 500-5000 pg (colorimetric). Recent experiments using the RIA have identified the principal antigenic determinants of vertebrate MTs as involving the immediate amino terminal residues (-MDPNC-) and the segment including residues 20-25 (-KCKECK- in human MT). Theoretical predictions of secondary structure based on hydrophilicity and sequence analysis indicate that the conformational profile is dominated by tetrapeptide candidates for beta turns (reverse turns) with 2-3 hexapeptide sequences being candidates for helical conformation and 4-5 short sequences (3-5 residues) being candidates for beta chain conformation. The helical candidates are predicted to be unstable and the analysis favors reverse turns for both determinants of vertebrate MT and a sequestered location for the joining region between clusters A and B.