Castigliego Lorenzo, Iannone Giorgio, Grifoni Goffredo, Rosati Remo, Gianfaldoni Daniela, Guidi Alessandra
Department of Animal Pathology, Prophylaxis and Food Hygiene, University of Pisa, Viale delle Piagge 2a, 56100 - Pisa, Italy.
J Dairy Res. 2007 Feb;74(1):79-85. doi: 10.1017/S0022029906002159. Epub 2006 Sep 15.
Bovine Somatotropin (bST) is a peptide hormone secreted by the anterior pituitary gland and its recombinant form (rbST) is used for artificially boosting milk yield in cows. Identification of rbST is difficult in that there is little difference from the pituitary bST (pbST). In this work, we further studied the possibility of immunologically discriminating between rbST and pbST. With this purpose, we produced mouse monoclonal antibodies using, as antigen, a peptide mimicking the N-terminus of rbST from Monsanto (rbST-M) conjugated to keyhole limpet haemocyanin (KLH) and polyclonal antibodies in rabbits immunized with the whole bST or rbST-M. Hence, we developed a sandwich ELISA with the obtained antibodies for detection and quantification of bST in serum and compared its performance on the two worldwide commercialized rbSTs: rbST-M and rbST from LG Life Science (rbST-LG). The lowest detection limit of the assay was 0.05 ng/ml for rbST-M, 0.10 ng/ml for rbST-LG and 0.15 ng/ml for pbST. Furthermore, the assay showed the capability to amplify the signal in the presence of rbSTs, recognizing more efficiently rbST-M and rbST-LG than pbST (ECn pbST/ECn rbST: 3 and 1.6 respectively). Its employment for measuring bST levels in sera from bovines administered with rbST LG allowed us to detect exceptional values due to the treatment itself and probably further increased as a consequence of the higher affinity for rbSTs of our monoclonal antibody.
牛生长激素（bST）是一种由垂体前叶分泌的肽类激素，其重组形式（rbST）被用于人工提高奶牛产奶量。rbST的鉴定存在困难，因为它与垂体bST（pbST）几乎没有差异。在这项工作中，我们进一步研究了通过免疫方法区分rbST和pbST的可能性。为此，我们使用与钥孔戚血蓝蛋白（KLH）偶联的孟山都公司的模拟rbST N端的肽（rbST-M）作为抗原制备了小鼠单克隆抗体，并使用完整的bST或rbST-M免疫兔子制备了多克隆抗体。因此，我们用获得的抗体开发了一种夹心ELISA，用于检测和定量血清中的bST，并比较了其对两种全球商业化的rbST：孟山都公司的rbST-M和LG生命科学公司的rbST（rbST-LG）的检测性能。该检测方法对rbST-M的最低检测限为0.05 ng/ml，对rbST-LG为0.10 ng/ml，对pbST为0.15 ng/ml。此外，该检测方法在存在rbST时能够放大信号，与pbST相比，对rbST-M和rbST-LG的识别效率更高（pbST的ECn/rbST的ECn分别为3和1.6）。将其用于测量注射了rbST-LG的牛血清中的bST水平，使我们能够检测到由于治疗本身导致的异常值，并且由于我们的单克隆抗体对rbST的亲和力更高，该值可能会进一步升高。
