Development of neo-biologics targeted on protein-protein interaction sites

为了开发新的治疗人类溶酶体组织蛋白A(cathepsin A，CATA)和神经氨酸酶-1(NEU1)缺乏(溶酶体储存性疾病)的药物，基于CATSA和NEU1之间的蛋白质-蛋白质相互作用，我们获得了在丝腺中部高表达人CATA和NEU1的转基因家蚕株，并成功地纯化和阐明了具有酶活性的CATA的X射线晶体结构。从TG丝腺中提纯的活性CASA与细胞穿透肽(R8)的结合物对CATA缺乏症患者培养的成纤维细胞具有替代作用，以减少唾液酸寡糖的积累。此外，西司他丁B被发现具有类似于伴侣化合物对重组人胞浆NEU2的稳定作用，其结构与NEU1相似。

To develop novel therapeutics for human deficiencies (lysosomal storage diseases) of lysosomal cathepsin A (CathA) and neuraminidase-1 (NEU1) based on protein-protein interaction between CathA and NEU1, we produced transgenic (Tg) silkworm strains overexpressing human CathA and NEU1 in middle silk glands, and succeeded in purification and elucidation of X-ray crystal structure of the enzymatically active CathA. The conjugates of active CathA purified from Tg silk glands and cell-penetrating peptides (R8) had replacement effects on cultured fibroblasts derived from patients with CathA deficiency (Galactosialidosis) to reduce the accumulated sialyloligosaccharides. In addition, siastatin B was found to have stabilizing effects like a chaperone compound on recombinant human cytosolic NEU2 with structural similarity to NEU1.