RESUMO
An effort was made to produce gelatin from Common carp wastes using extracted alkaline protease from Bacillus licheniformis PTCC 1595. Fermentation was performed by submerged media for 48 h and 72 h. The hydrolyzing enzyme was added in 5, 10, 15, 20, and 25 units per gram of wastes powder for hydrolysis. The produced gelatin was compared with commercial bovine gelatin with regard to some rheological and physicochemical properties. The yield of gelatin production was also determined as a result of hydroxyproline extraction from fish wastes. SDS-PAGE was performed for enzyme and gelatins. For enzyme, two bands were achieved with 39 and 10.5 kDa molecular weight which were separated passing through a 15 kDa UF filter. Both gelatins showed ß, α1, and α2 chains as basic components, but the fish waste gelatin showed narrow bands. In conclusion, foam expansion and water holding capacity were approximately equal in both gelatin types used for food industry application. The results indicated that using 20 units of enzyme per gram of waste powder was the optimum amount of enzyme application. Further, fish wastes were concluded to be a practical source for gelatin production.
RESUMO
BACKGROUND: Glutaminase (EC 3.5.1.2) catalyzes the hydrolytic degradation of L-glutamine to L-glutamic acid and has been introduced for cancer therapy in recent years. The present study was an in silico analysis of glutaminase to further elucidate its structure and physicochemical properties. METHODS: Forty glutaminase protein sequences from different species of Escherichia and Bacillus obtained from the UniProt Protein Database were characterized for homology search, physiochemical properties, phylogenetic tree construction, motif, superfamily search, and multiple sequence alignment. RESULTS: The sequence level homology was obtained among different groups of glutaminase enzymes, which belonged to superfamily serine-dependent ß-lactamases and penicillin-binding proteins. The phylogenetic tree constructed indicated 2 main clusters for the glutaminases. The distribution of common ß-lactamase motifs was also observed; however, various non-common motifs were also observed. CONCLUSION: Our results showed that the existence of a conserved motif with a signature amino-acid sequence of ß-lactamases could be considered for the genetic engineering of glutaminases in view of their potential application in cancer therapy. Nonetheless, further research is needed to improve the stability of glutaminases and decrease their immunogenicity in both medical and food industrial applications.
RESUMO
In recent years several bioconjugation protocols have been developed to improve the pharmacokinetic and immunological properties of anti-leukemic enzyme, L-asparaginase. In this study we investigated the effect of conjugation with oxidized inulin on these properties. Inulin (MW about 25kDa) was oxidized with periodate and was conjugated to the enzyme at molar ratios of oxidized inulin to enzyme between 2:1 and 4:1. Modified L-asparaginase synthesized at ratio of 2:1 had activity of 65% of that of native enzyme and was used in subsequent experiments. The apparent K(m) of glycoconjugate (0.1 x 10(-4)M) was about five times lower than the K(m) of native enzyme (0.57 x 10(-4)M). Modified L-asparaginase had longer half life, higher thermostability and more resistance to trypsin digestion and better reusability after repeated freezing and wider optimum pH range than that of intact L-asparaginase. The modification of L-asparaginase with oxidized inulin at molar ratio of 2:1 resulted in decreasing antibody (IgG) titer and immunogenecity after repeated injection of rabbits with respect to the native L-asparaginase. Taken together, the results of this study indicated that L-asparaginase modification by oxidized inulin results in a new stabilized product with improved biochemical properties which may be employed for medical purposes.