Screening, Purification And Properties Of Marine Algae Lectin

Ten Fujian marine algaes(six green,two red and two brown)were detected for hemagglutinins using erythrocytes of rabbit and chicken, inhibitory effect of PBS extracts on the infection of tobacco mosaic virus(TMV) on Nicotiana glutinosa and on the human stomach cancer MGc80-3.It showed that seven species inhibited the infection of TMV (the max effect up to 84.5%) , nine species were able to agglutinate native erythrocyte of rabbit and four species were able to agglutinate native erythrocyte of chicken among ten marine algaes.The marine algae lectins were more sensitive to erythrocyte of rabbit than to erythrocyte of chicken.Numerous algaes showed different fastness on the human stomach cancer MGc80-3.The inhibition rates of three species were higher than 50%.A new lectin ,named UPLl,was isolated and purified from the green marine algae Ulva Pertusa by extraction with PBS,followed by precipitation of 30%~80% saturation of (NH^SCU and an affinity chromatography on the Bovine-thyroglobulin-Sepharose 4B column. UPL1 was proved to be homogeneous by PAGE .By SDS-PAGE ,authour measured subunit raletive molecular mass to be about 23kD.The The inhibition rate of UPL1 on TMV and MGc80-3 is 56% and 51.5% (10 X ) respectively. The hemagglutinating activity for rabbit could be inhibited by albumin bovine and N-Acetyl-D-Glucosamine,the minimum inhibitory concentration was 5g/L and 2.765g/L. N-terminal sequence of this lectin was AGITNTDNWETFAGLPLTGA.No similar sequence was found in GenBank,The number is P83209.The antiserum of the lectin was prepared and thetiterwasl:214.The biochemical characteristics of UPL1 were researched. UPL1 contained 1.2% neutral sugar.lt was heat stable and kept a half activity at 80℃,with activity at pH6~9. The addition of divalent metals including Mn2+, Zn2+,Mg2+ influence the activity of the lectin.