Study On Proteomics Of The Skin Secretions Of Chinese Brown Frog (Rana Chensinensis)

Amphibian skin is a multifunctional organ acting in fluid balance, water regulation, respiration, temperature control, excretion, reproduction and antimicrobial defense. Protection of the skin from microbial invaders is essential for survival of individuals and populations. In response to stress or predator attack, amphibian skins secrete a complex chemical cocktail from highly specialized skin venom or granular glands, so amphibian skin is a natural barrier against the invasion of microorganisms and other pathogens in the environment via production of various bioactive molecules, such as alkaloids, biogenic amines, peptides and proteins. Therefore, these glands are thought to be one of the richest sources of bioactive peptides, exhibiting a broad spectrum of antimicrobial activity against Gram-positive and Gram-negative bacterium and cytotoxic activity responsible for inhibiting the growth of cancer cells.In this present study, Chinese brown frog(Rana chensinensis) distributes in northeast of China was used as experimental materials. The frog skin secretions were obtained by ether stimulation, or mild transdermal electrical stimulation, or injection of the hydrochloric norepinephrine into dorsal lymph sacs. The obtained skin secretions were used in analysis on proteomics after they were frozen in liquid nitrogen, lyophilized. The isolation and purification of single protein from the lyophilized skin secretions by two-dimensional electrophoresis (2DE) technology, and sequence analysis and characterization of protein by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. The results showed that the expressed proteins were different when we respectively used three methods to stimulate the frogs. We characterized prohormone convertase1, phenylalanyl-tRNA synthetase, tyrosine protein kinase, histidine kinase, protein phosphatase regulatory subunit, actin, phosphoglycerate kinase, macrophage migration inhibitory factor and aldo/keto reductase from skin secretions of Rana chensinensis,.They play a role in the Chinese brown frog skin immunity and defense process We expect these works give helps to understand physiological function and defence mechanism of frog skin.