A novel lipocalin homologue from the venom gland of Deinagkistrodon acutus similar to mammalian lipocalins

Wei CB (1, 2), Chen J (3)

(1) Department of Chemistry and Biology, Western Anhui University, Lu’an, Anhui Province, People’s Republic of China; (2) Lu’an Bionic Sensor and Testing Technique Laboratory of Anhui Province, Lu’an, Anhui Province, People’s Republic of China; (3) Faculty of Life Science and Biotechnology, Ningbo University, Ningbo, Zhejiang Province, People’s Republic of China.

Abstract: Lipocalins are involved in a variety of functions including retinol transport, cryptic coloration, olfaction, pheromone transport, prostaglandin synthesis, regulation of the immune response and cell homeostatic mediation. A full-length cDNA clone (named d-lipo), isolated from the venom gland cDNA library of Deinagkistrodon acutus, contained an insert of 664 bp including an open reading frame that encodes a lipocalin homologue of 177 amino acids. Comparison of d-lipo and other related proteins revealed an overall amino acid identity of less than 21.5%. Primary structures of d-lipo carried three structurally conserved regions (SCR) showing homologies to those of lipocalins. The first conserved Cys residue - the essential amino acid residue for the catalytic activity and unique to lipocalin-type prostaglandin D synthase (L-PGDS) in the lipocalin protein family - was identified in d-lipo at amino acid position 58. Phylogenetic tree analysis showed that d-lipo was in-between the large L-PGDS cluster and the small von Ebner’s-gland proteins (VEGP) cluster. Moreover, d-lipo gene presented a high-level expression in the venom gland and a low-level expression in the brain and its expression was significantly increased under pathological conditions, suggesting a possible relationship between d-lipo mRNA expression and the venom gland inflammatory disease. This is also the first report of a lipocalin homologous gene identified in the venom gland of a snake.

Key words: Deinagkistrodon acutus, cDNA library, lipocalin, phylogeny, gene expression pattern analysis.

ACKNOWLEDGEMENTS

We thank Dr. Zheng HY, Zhejiang Academy of Agricultural Sciences, Hangzhou, China, for help in cDNA library construction.

COPYRIGHT

© CEVAP 2012

SUBMISSION STATUS

Received: April 5, 2011.

Accepted: August 10, 2011.

Abstract published online: August 16, 2011.

Full paper published online: February 28, 2012.

CONFLICTS OF INTEREST

The authors declare no conflicts of interest.

FINANCIAL SOURCE

Natural Scientific Foundation of Anhui Province Education Commission (KJ2010A328) provided the financial grants.

ETHICS COMMITTEE APPROVAL

The present study was approved by the Ethics Committee of Western Anhui University, China.

CORRESPONDENCE TO

Chuanbao Wei, Department of Chemistry and Biology, Western Anhui University, Lu’an City 237012, Anhui Province, People’s Republic of China. Phone: +86 564 3305073. Fax: +86 564 3305033. Email: weichuanbao@sina.com or hsxz@wxc.edu.cn