Protein identification from the parotoid macrogland secretion of Duttaphrynus melanostictus

 

Douglas Oscar Ceolin Mariano¹, Marcela Di Giacomo Messias², Patrick Jack Spencer², Daniel Carvalho Pimenta¹

 

1 Laboratory of Biochemistry and Biophysics, Butantan Institute, São Paulo, SP, Brazil.

2 Biotechnology Center, Nuclear and Energy Research Institute (IPEN), São Paulo, SP, Brazil.

 

ABSTRACT

Background:

Bufonid parotoid macrogland secretion contains several low molecular mass molecules, such as alkaloids and steroids. Nevertheless, its protein content is poorly understood. Herein, we applied a sample preparation methodology that allows the analysis of viscous matrices in order to examine its proteins.

Methods:

Duttaphrynus melanostictus parotoid macrogland secretion was submitted to ion-exchange batch sample preparation, yielding two fractions: salt-displaced fraction and acid-displaced fraction. Each sample was then fractionated by anionic-exchange chromatography, followed by in-solution proteomic analysis.

Results:

Forty-two proteins could be identified, such as acyl-CoA-binding protein, alcohol dehydrogenase, calmodulin, galectin and histone. Moreover, de novo analyses yielded 153 peptides, whereas BLAST analyses corroborated some of the proteomic-identified proteins. Furthermore, the de novo peptide analyses indicate the presence of proteins related to apoptosis, cellular structure, catalysis and transport processes.

Conclusions:

Proper sample preparation allowed the proteomic and de novo identification of different proteins in the D. melanostictus parotoid macrogland secretion. These results may increase the knowledge about the universe of molecules that compose amphibian skin secretion, as well as to understand their biological/physiological role in the granular gland.

 

Keywords Amphibian skin secretion; Bufonidae; Duttaphrynus melanostictus; Proteomics; Batch chromatography; Asian common toad

 

Received: May 06, 2019.

Accepted: July 11, 2019.

 

Correspondence: dcpimenta@butantan.gov.br

 

Competing interests

The authors declare that they have no competing interests.

 

Authors' contributions

All the authors contributed equally in this work. All authors read and approved the final manuscript.