Miyashita S, Nomoto H, Konishi H, Hayashi K
Department of Molecular Biology, Gifu Pharmaceutical University, Japan.
Clin Chim Acta. 1994 Aug;228(2):71-81. doi: 10.1016/0009-8981(94)90278-x.
A sensitive two-site enzyme immunoassay (EIA) system was established for human pS2 protein, a small estrogen-inducible secretory protein of unknown function originally identified in MCF-7 human breast cancer cells. Our EIA system is based on the sandwiching of antigen between anti-recombinant (r) pS2 antibody IgG coated on a polystyrene plate and biotinylated anti-rpS2 antibody IgG. The amount of pS2 protein was quantified by measurement of the bound enzyme activity of subsequently added streptavidin-linked beta-D-galactosidase (beta-D-galactosidase, EC 3.2.1.23). pS2 protein purified from MCF-7 culture supernatants was detectable at a concentration as low as 3 pg/ml (corresponding to 60 fg/well). This EIA system revealed that the amount of pS2-like immunoreactivity (LI) in human urine was 13.6 ng/mg creatinine (median, n = 416) and that there was no correlation between the pS2-LI concentration in urine and sex or aging. pS2-LI levels in plasma and sera of the normal subjects were 392 pg/ml (median, n = 14) and 494 pg/ml (median, n = 12), respectively. The serum level of the patients with breast cancer (528 pg/ml; median, n = 67) was not statistically different from that of normal subjects, although high levels of pS2 protein in breast cancer tissues had been reported.
已建立一种灵敏的双位点酶免疫测定（EIA）系统，用于检测人pS2蛋白。pS2蛋白是一种小的雌激素诱导分泌蛋白，功能未知，最初在MCF-7人乳腺癌细胞中发现。我们的EIA系统基于包被在聚苯乙烯板上的抗重组（r）pS2抗体IgG和生物素化的抗rpS2抗体IgG之间夹着抗原。通过测量随后添加的链霉亲和素连接的β-D-半乳糖苷酶（β-D-半乳糖苷酶，EC 3.2.1.23）的结合酶活性来定量pS2蛋白的量。从MCF-7培养上清液中纯化的pS2蛋白在低至3 pg/ml（相当于60 fg/孔）的浓度下即可检测到。该EIA系统显示，人尿中pS2样免疫反应性（LI）的量为13.6 ng/mg肌酐（中位数，n = 416），并且尿中pS2-LI浓度与性别或年龄之间无相关性。正常受试者血浆和血清中的pS2-LI水平分别为392 pg/ml（中位数，n = 14）和494 pg/ml（中位数，n = 12）。尽管有报道称乳腺癌组织中pS2蛋白水平较高，但乳腺癌患者的血清水平（528 pg/ml；中位数，n = 67）与正常受试者相比无统计学差异。
