Frenken L G, van der Linden R H, Hermans P W, Bos J W, Ruuls R C, de Geus B, Verrips C T
Unilever Research Vlaardingen, The Netherlands.
J Biotechnol. 2000 Feb 28;78(1):11-21. doi: 10.1016/s0168-1656(99)00228-x.
Recently the existence of 'heavy chain' immunoglobulins in Camelidae has been described. However, as yet there is no data on the binding of this type of antibody to haptens. In addition, it was not a priori predictable whether the binding domains (VHH) of these antibodies could be produced and secreted by the lower eukaryotic micro-organism Saccharomyces cerevisiae. In the present study these questions are addressed. Heavy chain immunoglobulins directed against two hapten molecules, the azo-dyes RR6 and RR120 as well as the (proteinaceous) human pregnancy hormone, have been raised in Lama glama. We were able to select specific VHH fragments for all three antigens by direct screening of Escherichia coli or yeast libraries, even without prior enrichment via bio-panning. This is the first example of the isolation of llama anti-hapten VHH domains. Surprisingly, the affinities of the llama VHHs for the RR6 hapten obtained in this way are in the low nM range. Furthermore, some of the antigen specific VHHs were secreted by S. cerevisiae at levels over 100 mg l-1 in shake flask cultures. These two findings extend the possible application areas for the llama VHH fragments significantly.
最近，已经报道了骆驼科动物中存在“重链”免疫球蛋白。然而，关于这类抗体与半抗原结合的数据目前还没有。此外，这类抗体的结合结构域（VHH）是否能够由低等真核微生物酿酒酵母产生并分泌，在一开始是无法预测的。在本研究中，我们对这些问题进行了探讨。在羊驼体内产生了针对两种半抗原分子（偶氮染料RR6和RR120以及（蛋白质类）人妊娠激素）的重链免疫球蛋白。我们通过直接筛选大肠杆菌或酵母文库，能够为所有三种抗原选择特异性VHH片段，甚至无需通过生物淘选进行预先富集。这是羊驼抗半抗原VHH结构域分离的首个实例。令人惊讶的是，以这种方式获得的羊驼VHH对RR6半抗原的亲和力处于低纳摩尔范围。此外，在摇瓶培养中，一些抗原特异性VHH由酿酒酵母分泌的水平超过100 mg l-1。这两个发现显著扩展了羊驼VHH片段可能的应用领域。
