Abstract
We have isolated a novel type of lectin named Arenicola marina lectin-1 (AML-1) from the lugworm A. marina. The lectin was purified from the coelomic fluid by affinity chromatography on a GlcNAc-derivatized column and eluted with GlcNAc. On SDS-PAGE, AML-1 showed an apparent molecular mass of 27 and 31 kDa in the reduced state. The N-terminal amino acid sequences were identical in these two bands. In the unreduced state, a complex band pattern was observed with bands from 35 kDa to more than 200 kDa. Two different full-length clones encoding polypeptides of 241 and 243 amino acids, respectively, were isolated from a coelomocyte cDNA library. The two clones, designated AML-1a and AML-1b, were 92% identical at the protein level and represent a novel type of protein sequence family. Purified AML-1 induced agglutination of rabbit erythrocytes, which could be inhibited by N-acetylated saccharides. Recombinant AML-1b showed the same band pattern as the native protein, whereas recombinant AML-1a in the reduced state lacked a 27 kDa band. AML-1b bound GlcNAc-derivatized columns and chitin, whereas AML-1a did not bind to these matrices. Immunohistochemical analysis revealed that AML-1 is expressed by coelomocytes in the nephridium and in round cells in the epidermis and in eggs. Moreover, AML-1 expression was up-regulated in response to a parasitic infection. We conclude that AML-1 purified from coelomic fluid is encoded by AML-1b and represents a novel type of protein family that binds acetylated components.
Original language | English |
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Journal | Journal of Biological Chemistry |
Volume | 287 |
Issue number | 51 |
Pages (from-to) | 42846-55 |
Number of pages | 10 |
ISSN | 0021-9258 |
DOIs | |
Publication status | Published - 14 Dec 2012 |
Keywords
- Amino Acid Sequence
- Animals
- Body Fluids
- CHO Cells
- Chitin
- Cloning, Molecular
- Cricetinae
- DNA, Complementary
- Electrophoresis, Polyacrylamide Gel
- Erythrocytes
- Glucosamine
- Helminth Proteins
- Helminths
- Hemagglutination Inhibition Tests
- Immunohistochemistry
- Molecular Sequence Data
- Peptides
- Protein Binding
- Rabbits
- Recombinant Proteins
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Analysis, Protein
- Sequence Homology, Amino Acid