Ippoliti R, Lendaro E, Bellelli A, Fiani M L, Benedetti P A, Evangelista V, Brunori M
Dipartimento di Scienze Biochimiche e Centro di Biologia Molecolare del CNR, Università La Sapienza, Rome, Italy.
Nat Toxins. 1996;4(4):156-62. doi: 10.1002/19960404nt2.
Saporin, a single-chain, non-cytotoxic, ribosome-inactivating protein from Saponaria officinalis, was chemically linked to the hormone insulin in a 1:1 complex. To follow by dynamic video microscopy the endocytosis and intracellular transport in vivo, a second covalent conjugate with a saporin derivative labelled with fluorescein isothiocyanate was also prepared. Both conjugates were characterized with reference to homogeneity, stoichiometry, optical spectroscopy and toxicity. Both were found to exhibit scarce toxicity toward both CHO and HEP G2 cells; optical video microscopy on living cells indicates that reduced toxicity may be (partly) due to a very limited binding of the saporin-insulin conjugate to membrane receptors. These results suggest a strategy for new possible covalent conjugates of saporin with alternative and specific macromolecular carriers.
皂草素是一种来自肥皂草的单链、无细胞毒性的核糖体失活蛋白，它与激素胰岛素以1:1的复合物形式化学连接。为了通过动态视频显微镜观察体内的内吞作用和细胞内运输，还制备了一种与异硫氰酸荧光素标记的皂草素衍生物的第二个共价缀合物。两种缀合物均通过均一性、化学计量学、光谱学和毒性进行了表征。发现两者对CHO和HEP G2细胞均表现出极低的毒性；对活细胞的光学视频显微镜观察表明，毒性降低可能（部分）是由于皂草素-胰岛素缀合物与膜受体的结合非常有限。这些结果提示了一种新的可能策略，即制备皂草素与替代的特异性大分子载体的共价缀合物。
