Novel surfactant proteins are involved in the structure and stability of foam nests from the frogLeptodactylus vastus
Author:
Hissa Denise Cavalcante1, Vasconcelos Ilka Maria2, Carvalho Ana Fontenele Urano1, Nogueira Vanessa Lúcia Rodrigues1, Cascon Paulo1, Antunes André Saraiva Leão1, de Macedo Gorete Ribeiro3, Melo Vânia Maria Maciel1
Affiliation:
1. Departamento de Biologia, Universidade Federal do Ceará, Av. Humberto Monte 2775 Campus Pici, Bloco 909, Fortaleza, Brazil, 60455-000 2. Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus Pici, Fortaleza, Brazil 3. Departamento de Engenharia Química, Universidade Federal do Rio Grande do Norte, Natal, Brazil
Abstract
SUMMARYMany amphibians lay their eggs in foam nests, which allow the eggs to be deposited out of the water. Analysis of some of these foam nests has revealed that they are a rich source of proteins with unusual primary structures and remarkable surfactant activity, named ranaspumins. The aim of this work was to study the foam nests of the frog Leptodactylus vastus in order to obtain information regarding their composition and function and to improve the understanding of ranaspumins, which are probably a novel class of surfactant proteins. Analyses of the foam fluid composition showed proteins and carbohydrates that presumably are responsible for providing nutrients for the developing tadpoles. Investigation of the function of foam fluid in chemical defence revealed no significant biological activity that could be associated with recognized defence compounds. However, foam fluid presented UV absorbance, suggesting a role in protection against sun damage, which is considered to be one of the possible causes of recently reported amphibian population declines. The foam nests do not prevent the colonization of microorganisms, such as the observed bacterial community of predominantly Gram-positive bacilli. L. vastus foam fluid shows a strong surfactant activity that was associated with their proteins and this activity seems to be due mainly to a protein named Lv-ranaspumin. This protein was isolated by ion-exchange chromatography and found to be a 20 kDa monomeric molecule with the following N-terminal sequence: FLEGFLVPKVVPGPTAALLKKALDD. This protein did not show any match to known proteins or structures, which suggests that it belongs to a new class of surfactant protein.
Publisher
The Company of Biologists
Subject
Insect Science,Molecular Biology,Animal Science and Zoology,Aquatic Science,Physiology,Ecology, Evolution, Behavior and Systematics
Reference44 articles.
1. Andrade, D. V. and Abe, A. S. (1997). Foam nest production in the armoured catfish. J. Fish. Biol.50,665-667. 2. Altschul, S. F., Madden, T. L., Schäffer, A. A., Zhang, J.,Zhang, Z., Miller, W. and Lipman, D. J. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res.25,3389-3402. 3. Bauer, A. W., Kirby, W. M., Sherris, J. C. and Turck, M.(1966). Antibiotic susceptibility testing by a standardized single disc method. Am. J. Clin. Pathol.45,493-496. 4. Becerril, B., Corona, M., Coronas, F. I. V., Zamudio, F.,Calderon-Aranda, E. S., Fletcher, P. L., Martin, B. M. and Possani, L. D.(1996). Toxic peptides and genes encoding toxin gamma of the Brazilian scorpions Tityus bahiensis and Tityus stigmurus.Biochem. J.313,753-760. 5. Blaustein, A. R. and Belden, L. K. (2003). Amphibian defenses against ultraviolet-B radiation. Evol. Dev.5,89-97.
Cited by
30 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|