title: Protein turnover, amino acid profile and amino acid flux in juvenile shrimp Litopenaeus vannamei: effects of dietary protein source.
abstract: The effect of dietary protein on protein synthesis and growth of juvenile shrimps Litopenaeus vannamei was investigated using three different diets with equivalent protein content. Protein synthesis was investigated by a flooding dose of tritiated phenylalanine. Survival, specific growth and protein synthesis rates were higher, and protein degradation was lower, in shrimps fed a fish/squid/shrimp meal diet, or a 50% laboratory diet/50% soybean meal variant diet, than in those fed a casein-based diet. The efficiency of retention of synthesized protein as growth was 94% for shrimps fed the fish meal diet, suggesting a very low protein turnover rate; by contrast, the retention of synthesized protein was only 80% for shrimps fed the casein diet. The amino acid profile of the casein diet was poorly correlated with that of the shrimps. 4 h after a single meal the protein synthesis rates increased following an increase in RNA activity. A model was developed for amino acid flux, suggesting that high growth rates involve a reduction in the turnover of proteins, while amino acid loss appears to be high.
authors.affiliation: Department of Zoology, University of Aberdeen, Tillydrone Avenue, Scotland, UK. e.mente@abdn.ac.uk
authors.forename: Eleni
authors.initials: E
authors.lastname: Mente
authors.forename: Peter
authors.initials: P
authors.lastname: Coutteau
authors.forename: Dominic
authors.initials: D
authors.lastname: Houlihan
authors.forename: Ian
authors.initials: I
authors.lastname: Davidson
authors.forename: Patrick
authors.initials: P
authors.lastname: Sorgeloos
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000378:metabolism*; D000818:Animals; D002364:Caseins / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D007700:Kinetics; D033561:Penaeidae / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000032:analysis; D030262:Soybean Proteins / Q000008:administration & dosage; D014316:Tritium
chemical_list: D000596:Amino Acids; D002364:Caseins; D004044:Dietary Proteins; D011506:Proteins; D030262:Soybean Proteins; D014316:Tritium; D010649:Phenylalanine; D012313:RNA