A normal mucin-binding lectin from the sponge Craniella australiensis.
A lectin, Craniella australiensis (CAL), was isolated from sponge C. australiensis by ion-exchange on DEAE-Sephacel and purified by gel filtration on Sephadex G-150 and HPLC on DEAE-5PW. The purified lectin was a trimeric protein as revealed by SDS-PAGE and MALDI-TOF analysis. SDS-PAGE showed that the CAL protein had a molecular mass of 54 kDa, and consisted of three 18 kDa subunits. Gel filtration of purified lectin on Sephadex G-200 indicates that it exists as a 54 kDa protein in its native state. The amino acid composition was rich in Thr and Glx. CAL was found to agglutinate native and trypsinized human A, B erythrocytes, and agglutinate native erythrocytes of mouse, sheep, rabbit and chicken, and trypsinized erythrocytes of sheep and rabbit. The hemagglutination activity was inhibited by glycoproteins such as PSM and asialo-PSM, but not by any of the monosaccharides tested. The activity was stable between 20 and 70 degrees C. Significant CAL activity was observed between pH 5 and 8. The lectin reaction is independent of the presence of divalent cations Ca2+ and Mg2+. The sequence of N-terminal residues of CAL was determined as TSSCQSIVVE. The lectin showed a potent mitogenic response towards BALB/c splenocytes.
Dalian Institute of Chemical Physics, Chinese Academy of Science, Liaoning Dalian 116023, PR China.
Chuannan
C
Xiong
Wei
W
Li
Han
H
Liu
Wei
W
Zhang
Jiangli
J
Dou
Xuefang
X
Bai
Yuguang
Y
Du
Xiaojun
X
Ma
D000595:Amino Acid Sequence; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006023:Glycoproteins / Q000494:pharmacology; D006386:Hemagglutination Tests; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009077:Mucins / Q000378:metabolism*; D011161:Porifera / Q000737:chemistry*; D013154:Spleen / Q000166:cytology / Q000187:drug effects; D013696:Temperature
D006023:Glycoproteins; D037102:Lectins; D009077:Mucins