Separation and some properties of Aloe vera L. leaf pulp lectins

✍ Scribed by Nuriye Akev; Ayşe Can

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 64 KB
• Volume: 13
• Category: Article
• ISSN: 0951-418X
• DOI: 10.1002/(sici)1099-1573(199909)13:6<489::aid-ptr499>3.0.co;2-5

✦ Synopsis

The separation and partial purification of two lectins from the leaf pulp of Aloe vera L. (=barbadensis Miller) is presented. The fraction showing haemagglutinating activity was precipitated at 50% ammonium sulphate concentration from the crude leaf pulp extract. The precipitate thus obtained, after dialysis, was applied to a hydroxylapatite column. Stepwise elution resulted in two peaks showing haemagglutinating activity eluted with 5 mM (Aloctin I) and 20 mM (Aloctin II) phosphate buffers. Haemagglutinating activity was estimated visually by adding a 4% rabbit erythrocyte suspension to serial two-fold dilutions of the lectins in microtitration plates. None of the 20 sugars tested inhibited haemagglutinating activity of Aloctin I up a concentration of 500 mM. Aloctin II was inhibited by N-acetyl-Dgalactosamine at 250 mM concentration. Of 10 metal ions tested, only Al 3 salts were found to activate Aloctin I and II. On the other hand, it was shown that neither lectin possessed any aand bgalactosidase or aand bglucosidase activity. The lectins were of glycoprotein structure containing approximately 5% neutral sugar. The specificity of the lectins towards human and rat erythrocytes was investigated.