Potencial ação inseticida e caracterização bioquímica de uma ficoeritrina isolada da macroalga vermelha Hypnea musciformis

Abstract

Agriculture in the 21st century seeks to produce more food to meet the need for a growing population with a smaller rural workforce. This population increase is accompanied by increasing investments in agricultural production and, consequently, in the use of insecticides that aim to guarantee pest management, as these pests can progressively and dangerously affect this investment. The problem with the use of chemical pesticides is the harzard caused to environment and human life, as their use can directly interfere in decrease of species biodiversity or even contribute to the emergence of resistant species that cause irreversible damage to the environment. There is a great effort to reduce the risk of human exposure to pesticides, some studies even focus on safer and more selective insecticides for natural pests. The demand for insecticides with new modes of action and formulations is being developed and registered based on strict regulations, considering environment and non-target species safety. The prospection of other molecules that present insecticidal activity is a main goal of the scientific community, as it would make possible the use alternatives that are less aggressive to the environment and to the human being itself. In this sense, the insecticidal activity of a phycobiliprotein, HMLp, purified from Hypnea musciformis, against insect cells of Drosophyla melanogaster strain S2 and Choristoneura fumiferana strain CF1 was evaluated. The protein showed cell growth inhibition activity of Drosophila melanogaster S2 after 48 hours of incubation. Regarding Choristoneura fumiferana strain CF1, HMLp did not inhibit cell growth when compared to the control. The biochemical characterization of HMLp showed that this protein is a heterodimer composed of two subunits called alpha and beta, with an apparent molecular mass of 20 and 22 kDa, respectively. HMLp showed stability up to 100 ºC of temperature, stability in the pH range of 6.0 to 9.0 and specificity for N-glycans. HMLp was classified as phycoerythrin from peptide sequencing data using mass spectrometry with MALDI ionization source. These preliminary tests suggest that HMLp may be a potential tool in studies as an insecticidal agent in other biological models.