Use of immunoglobulin-loaded protein A-bearing staphylococci as a primary solid phase immunoadsorbent in radioimmunoassay.
Use of immunoglobulin-loaded protein A-bearing staphylococci as a primary solid phase immunoadsorbent in radioimmunoassay.
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负载免疫球蛋白的 A 蛋白葡萄球菌作为放射免疫测定中的主要固相免疫吸附剂的用途。
DOI：
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发表时间：
1980
影响因子：
4.8
通讯作者：
V. Vennett
中科院分区：
文献类型：
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作者：
E. O'Keefe;V. Vennett
含A蛋白的甲醛灭活金黄色葡萄球菌结合兔125 I-IgG的能力较强。固定化IgG对抗原的亲和力等于可溶性抗体的亲和力，对抗原的容量接近可溶性抗体对抗原的容量。在4 ℃下4小时后，在人血清存在下，与细菌上的高亲和力位点结合的125 I-IgG基本上不被置换，但兔免疫球蛋白可以置换结合的兔IgG。携带蛋白A的细菌在抗血清中吸附了无蛋白酶活性的IgG，为放射免疫分析提供了一种稳定、灵敏、具有独特功能的初级固相吸附剂。细菌的沉降特性允许通过离心一抗将结合配体与游离配体容易地分离。负载免疫球蛋白的葡萄球菌可以从血清中吸附配体，同时纯化和浓缩配体以在单个后续步骤中进行测量。携带免疫球蛋白的细菌可以直接用于含有免疫球蛋白的生物流体，例如血清和培养基。与传统的固相吸附剂相比，使用免疫球蛋白负载的葡萄球菌的放射免疫测定具有更好的经济性、低非特异性结合、高功能容量、稳定性和独特的特性。
Protein A-bearing formalinized heat-inactivated Staphylococcus aureus bind rabbit 125I-IgG with high capacity of IgG for antigen. The affinity of immobilized IgG for antigen is equal to the affinity of soluble antibody, and the capacity for antigen approximates the capacity of soluble antibody for antigen. 125I-IgG bound to high affinity sites on bacteria is not substantially displaced in the presence of human serum after 4 h at 4 degrees C, but rabbit immunoglobulin can displace bound rabbit IgG. Protein A-bearing bacteria which have adsorbed IgG free from protease activity in antiserum provide a stable, sensitive, primary solid phase adsorbent with unique features for radioimmunoassay. Sedimentation characteristics of bacteria permit facile separation of bound from free ligand by centrifugation of the primary antibody. Immunoglobulin-loaded staphylococci can adsorb ligand from serum, simultaneously purifying and concentrating ligands for measurement in a single subsequent step. Immunoglobulin-bearing bacteria can be used directly in biological fluids containing immunoglobulin, such as serum and culture media. Improved economy of staphylococci, low nonspecific binding, high functional capacity, stability, and unique characteristics of radioimmunoassay using immunoglobulin-loaded staphylococci compare favorably with conventional solid phase adsorbents.