Publications (3)4.69 Total impact
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Article: Lobster (Panulirus argus) hepatopancreatic trypsin isoforms and their digestion efficiency.
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ABSTRACT: It is well known that crustaceans exhibit several isoforms of trypsin in their digestive system. Although the number of known crustacean trypsin isoforms continues increasing, especially those derived from cDNA sequences, the role of particular isoenzymes in digestion remains unknown. Among invertebrates, significant advances in the understanding of the role of multiple trypsins have been made only in insects. Since it has been demonstrated that trypsin isoenzyme patterns (phenotypes) in lobster differ in digestion efficiency, we used this crustacean as a model for assessing the biochemical basis of such differences. We demonstrated that the trypsin isoform known to be present in all individuals of Panulirus argus has a high catalytic efficiency (k(cat)/K(m) ) and is the most reactive toward native proteinaceous substrates, whereas one of the isoforms present in less efficient individuals has a lower k(cat) and a lower k(cat)/K(m), and it is less competent at digesting native proteins. A fundamental question in biology is how genetic differences produce different physiological performances. This work is the first to demonstrate that trypsin phenotypic variation in crustacean protein digestion relies on the biochemical properties of the different isoforms. Results are relevant for understanding trypsin polymorphism and protein digestion in lobster.Biological Bulletin 04/2012; 222(2):158-70. · 1.70 Impact Factor -
Article: Dietary protein quality differentially regulates trypsin enzymes at the secretion and transcription level in Panulirus argus by distinct signaling pathways.
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ABSTRACT: The effects of pelleted diets with different protein composition (fish, squid or soybean meals as main protein sources) on trypsin secretion and expression were studied in the lobster Panulirus argus. Trypsin secretion was shown to be maximal 4 h after ingestion. At this time, fish- and squid-based diets induced trypsin secretion, as well as up-regulation of the major trypsin isoform at the transcription level. While fish- and squid-based diets elicited a prandial response, soybean-based diet failed to stimulate the digestive gland to secrete trypsin into the gastric fluid or induce trypsin expression above the levels observed in fasting lobsters. In vitro assays showed that intact proteins rather than protein hydrolysates stimulate trypsin secretion in the lobster. However, the signal for trypsin transcription appears to be different to that for secretion and is probably mediated by the appearance of free amino acids in the digestive gland, suggesting a stepwise regulation of trypsin enzymes during digestion. We conclude that trypsin enzymes in P. argus are regulated at the transcription and secretion level by the quality of dietary proteins through two distinct signaling pathways. Our results indicate that protein digestion efficiency in spiny lobsters can be improved by selecting appropriated protein sources. However, other factors like the poor solubility of dietary proteins in dry diets could hamper further enhancement of digestion efficiency.Journal of Experimental Biology 03/2012; 215(Pt 5):853-62. · 3.00 Impact Factor -
Article: Invertebrados marinos de la zona central del golfo de Ana María, Cuba
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ABSTRACT: Nowadays there is little information about the biological diversity in the Ana Maria gulf. Most of the research in that region has been focused on fisheries and the hydrological character. Thus in 2011 a research project was initiated to fill this information gap. This paper presents a list of 105 species of marine invertebrates identified in the central part of the Ana Maria gulf. The mollusks was the best represented group of invertebrate’s animal with 43 species that represented a 40.9% of the total, followed by the echinoderms with 26 species and 24.8% of the total. The largest keys (Cuervo, Algodón Grande y Bergantines) harbored the highest species richness. These results provided a baseline for future research to deepen the study of the diversity and ecology of marine invertebrates in the sampled area and other areas of the gulf.Revista de Investigaciones Marinas. 01/2012; 32(2):30-38.
