Potencial of fermented milk for anti-adhesion therapy

在本课题开始之前，我们已经发现卷曲乳杆菌JCM 5810具有良好的粘附性，其43-kDa的S层蛋白（CbsA）被鉴定为粘附素，1997年通过DNA测序确定了CbsA的一级结构。非粘附性嗜酸乳杆菌1CM 1132（=ATCC 4356）的CbsA和S层蛋白（SIpA）的比对表明，除了一个残基之外，30个氨基酸的信号序列是相同的。两种蛋白C端序列同源性为77%，N端序列同源性为30%。1998年对CbsA基因进行了缺失和点突变，并对表达的His-tag融合蛋白进行了与IV型胶原结合的鉴定。结果表明，1- 287个氨基酸序列是结合IV型胶原所必需的。Lb.以Crispatus JCM 5810及其S-层蛋白抑制肠源性大肠杆菌在基质胶和固定化层粘连蛋白上的粘附作为粘膜下模型，上述结果表明，携带S-层的乳酸杆菌及其S-层蛋白有可能应用于抗粘附治疗肠道感染性疾病的药物。

Before this project had started, we had shown that Lactobacillus crispatus JCM 5810 well adhered to submucosal model and its 43-kDa S-layer protein(CbsA) had been identified as an adhesin.In the year 1997 primary structure of CbsA was determined by DNA sequencing. Alignment of CbsA and S-layer protein(SIpA) of non-adhesive Lactobacillus acidophilus 1CM 1132(=ATCC 4356) indicated that signal sequence of 30 amino acids was identical except one residue. The identity of two proteins was 77% in C-terminal sequence and 30% in N-terminal region. These results suggested binding region might be located in the N-terminal region.In the year 1998 deletion and point mutation was incorporated into CbsA gene and the expressed His-tag fusion protein was evaluated for binding to type IV collagen. The results suggested that 1-2 87 amino acid sequence was necessary to bind type IV collagen. Lb. crispatus JCM 5810 and its S-layer protein inhibited the adherence of enterotoxigenic Escherichia coli on Matrigel and immobilized laminin, used as an submucosal model.The above results suggested S-layer-bearing lactobacillar strains and their S-layer protein have the potential to apply anti-adhesion theraputic agent for intestinal infection disease to inhibite collonization of pathogens.