Tashiro K, Monji A, Yoshida I, Hayashi Y, Matsuda K, Tashiro N, Mitsuyama Y
Department of Psychiatry, Miyazaki Medical College, 5200, Kihara, Kiyotake-cho, Miyazaki-gun, Miyazaki, 889-1692, Japan.
Biochem J. 1999 May 15;340 ( Pt 1)(Pt 1):119-26.
We synthesized and characterized several peptides containing the IKLLI sequence in the alpha1 chain of laminin-1. The IKLLI-containing peptides, such as LA4 (CSRNLSEIKLLISRARK), LA5 (EIKLLIS) and LA5L (SEIKLLIS), were found to mediate heparin binding and cell adhesion, while also promoting neurite outgrowth in PC12 cells. Furthermore, peptides LA4 and LA5 also mediated proliferation. However, a scrambled peptide, LA5S (ILEKSLI), did not show any of these activities. Anti-LA4 antibodies inhibited laminin- and LA5-mediated cell adhesion and neurite outgrowth, and anti-(integrin alpha3) and anti-(integrin beta1) antibodies inhibited LA5-mediated cell adhesion and neurite outgrowth. Heparin and heparan sulphate inhibited LA5-mediated heparin binding and PC12 cell adhesion in a dose- dependent manner. The IC50 for inhibition of heparin binding and cell adhesion was observed with 9 microM and 8 microM heparin/heparan sulphate respectively. Furthermore, heparan sulphate proteoglycan also inhibited LA5-mediated PC12 cell adhesion with an IC50 of 100 micrograms/ml. However, chondroitin sulphate (dermatan sulphate) did not inhibit cell adhesion. These data suggest that an IKLLI-containing peptide derived from the laminin alpha1 chain may be an active site of laminin and that its cell adhesion may thus interact with both integrin alpha3beta1 and cell- surface heparan sulphate proteoglycan.
我们合成并表征了层粘连蛋白-1 α1链中含有IKLLI序列的几种肽。发现含IKLLI的肽，如LA4（CSRNLSEIKLLISRARK）、LA5（EIKLLIS）和LA5L（SEIKLLIS），可介导肝素结合和细胞黏附，同时还能促进PC12细胞的神经突生长。此外，肽LA4和LA5还介导细胞增殖。然而，一种乱序肽LA5S（ILEKSLI）未表现出任何这些活性。抗LA4抗体抑制层粘连蛋白和LA5介导的细胞黏附和神经突生长，抗（整合素α3）和抗（整合素β1）抗体抑制LA5介导的细胞黏附和神经突生长。肝素和硫酸乙酰肝素以剂量依赖方式抑制LA5介导的肝素结合和PC12细胞黏附。分别在9 microM和8 microM肝素/硫酸乙酰肝素时观察到抑制肝素结合和细胞黏附的IC50。此外，硫酸乙酰肝素蛋白聚糖也以100微克/毫升的IC50抑制LA5介导的PC12细胞黏附。然而，硫酸软骨素（硫酸皮肤素）不抑制细胞黏附。这些数据表明，源自层粘连蛋白α1链的含IKLLI肽可能是层粘连蛋白的一个活性位点，其细胞黏附可能因此与整合素α3β1和细胞表面硫酸乙酰肝素蛋白聚糖相互作用。
