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A preduodenal esterase was purified to homogeneity from turkey (Meleagris gallopavo) pharyngial tissue. Pure turkey pregastric esterase (TPrE) was obtained after anion exchange chromatography (DEAE-cellulose), Sephacryl S-200 gel filtration, anion exchange chromatography (Mono-Q sepharose) and affinity chromatography (Blue-Gel Affi Gel). The pure e...
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... This cofactor exposes the hydrophobic tips of its fingers at the opposite side of its lipase-binding site through noncovalent interactions [10,13]. In recent years, researchers have been seeking to widen the study of pancreatic lipases from birds [8,16] and invertebrates [14,17,18]. The turkey pancreatic lipase (TPL) shows the same features of HPL, and its three-dimensional structure consists of two domains stabilized by six disulphide bridges [8]. ...
A full-length cDNA encoding digestive lipase (SmDL) was cloned from the pancreas of the smooth-hound (Mustelus mustelus). The obtained cDNA was 1350 bp long encoding 451 amino acids. The deduced amino acid sequence has high similarity with known pancreatic lipases. Catalytic triad and disulphide bond positions are also conserved. According to the established phylogeny, the SmDL was grouped with those of tuna and Sparidae lipases into one fish digestive lipase cluster. The recently purified enzyme shows no dependence for bile salts and colipase. For this, the residue-level interactions between lipase-colipase are yet to be clearly understood. The structural model of the SmDL was built, and several dissimilarities were noticed when analyzing the SmDL amino acids corresponding to those involved in HPL binding to colipase. Interestingly, the C-terminal domain of SmDL which holds the colipase shows a significant role for colipase interaction. This is apt to prevent the interaction between fish lipase and the pancreatic colipase which and can provide more explanation on the fact that the classical colipase is unable to activate the SmDL.
... This can be achieved using pH-dependent protections such as free fatty acid matrices or non-protective matrices coated with pH-sensitive polymers (Ji et al., 2007;Vervaeck et al., 2013). Also tributyrin, the triglyceride analogue of butyrate, can be considered as a targeted release formulation due to the low pre-duodenal lipolytic activity of broiler's GIT (Cherif et al., 2006;. Sustained release refers to the prolonged release of an active compound over time based on enzymatic or mechanic erosion and diffusion mechanisms. ...
... This is in agreement with other published results on broilers . Tributyrin, the triglyceride of butyrate, only increased enteric butyrate concentration in the present study due to a low pre-duodenal lipolytic activity in the broiler GIT Cherif et al., 2006). Finally, fat-coated butyrate numerically increased butyrate concentration in the pooled colon and ceca contents when compared to birds fed other butyrate additives (+22.9 %; P=0.204). ...
... This is in agreement with other published results on broilers (Hu and Guo, 2007;Smith et al., 2012). Tributyrin, the triglyceride of butyrate, only increased enteric butyrate concentration in the present study due to a low pre-duodenal lipolytic activity in the broiler GIT (Moreau et al., 1988;Cherif et al., 2006). Finally, fat-coated butyrate numerically increased butyrate concentration in the pooled colon and ceca contents when compared to birds fed other butyrate derivatives (+22.9%; ...
The hypothesis was tested that butyrate presence in the digesta of distinct gastrointestinal tract (GIT) segments of broilers leads to differential effects on digesta retention time, gut morphology, and proteolytic enzymatic activities, ultimately resulting in differences in protein digestibility. A total of 320 male day-old Ross 308 broilers were randomly assigned to 5 dietary treatments: 1) control (no butyrate), 2) unprotected butyrate (main activity in the crop and gastric regions), 3) tributyrin (main activity in the small intestine), 4) fat-coated butyrate (activity in the whole GIT) and 5) unprotected butyrate combined with tributyrin, each replicated 8 times. Rapeseed meal was used in combination with a fine dietary particle size in order to challenge the digestive capacity of young broilers. Birds were dissected at 22, 23, and 24 d of age and samples of digesta at various GIT locations as well as tissues were collected. Butyrate concentration varied significantly across GIT segments depending on treatment, indicating that the dietary contrasts were successful. The apparent ileal digestibility of methionine tended to increase when butyrate and/or propionate was present in colonic and cecal contents, possibly due to modifications of GIT development and digesta transit time. Butyrate presence in the digesta of the crop, proventriculus and gizzard, on the contrary, decreased the apparent ileal digestibility of several amino acids (AA). In addition, butyrate presence beyond the gizzard elicited anorexic effect that might be attributable to changes in intestinal enteroendocrine L-cells secretory activities. The present study demonstrates that, in broilers, effects of butyrate on digestive processes are conditioned by the GIT segment wherein the molecule is present and indicates its influence on digestive function and bioavailability of AA.
An esterase was purified from the golden grey mullet viscera using successively a Sephacryl S-100 gel filtration, an anion-exchange chromatography and a high-performance liquid chromatography filtration column. The pure esterase (GmDE) is a monomer that has a molecular mass of about 55 kDa, as determined by SDS-PAGE analysis. The purified enzyme displayed a specific activity of 100 U/mg on short-chain triacylglycerols at a temperature of 50C. GmDE is therefore a thermoactive enzyme as compared to other fish lipolytic enzymes that have been studied so far. No significant lipolytic activity was noticed when long-chain triacylglycerol (olive oil) was used as a substrate. It is worth noting that the pure esterase was active in the presence of salt concentrations as high as 0.8 M. The GmDE N-terminal amino acid sequence showed no similarities with that of other known fish esterases. Altogether, these results suggest that the GmDE is a member of a new group of digestive esterases belonging to vertebrates.Practical ApplicationsCharacterization of an esterase from low-value fish viscera and the use of digestive enzyme may add value to this discarded species. Furthermore, the activity and stability at alkaline pH may also find use in laundry detergents. The thermoactivity of the purified esterase makes it a good candidate for potential application in food processing operations. Finally, the stability of the enzyme in high salt concentrations suggests that it can be used as an additive in different processes (food, cosmetic and pharmaceutical operations).
A lipolytic activity was located in the chicken uropygial glands, from which a carboxylesterase (CUE) was purified. Pure CUE has an apparent molecular mass of 50 kDa. The purified esterase displayed its maximal activity (200 U/mg) on short-chain triacylglycerols (tributyrin) at a temperature of 50°C. No significant lipolytic activity was found when medium chain (trioctanoin) or long chain (olive oil) triacylglycerols were used as substrates. The enzyme retained 75% of its maximal activity when incubated during 2h at 50°C. The NH(2)-terminal amino acid sequence showed similarities with the esterase purified recently from turkey pharyngeal tissue. Esterase activity remains stable after its incubation during 30 min in presence of organic solvents such as hexane or butanol. CUE is a serine enzyme since it was inactivated by phenylmethanesulphonyl fluoride (PMSF), a serine-specific inhibitor. The purified enzyme, which tolerates the presence of some organic solvent and a high temperature, can be used in non-aqueous synthesis reactions. Hence, the uropygial esterase immobilised onto CaCO(3) was tested to produce the isoamyl and the butyl acetate (flavour esters). Reactions were performed at 50°C in presence of hexane. High synthesis yields of 91 and 67.8% were obtained for isoamyl and butyl acetate, respectively.
Stability is a crucial factor for the application of enzymes in biotechnology. Investigation of esterase activity in the pharyngeal tissue of turkey (Meleagris gallopavo), showed that optimum catalytic conditions of pure enzyme were 50 degrees C and pH 8.5. Turkey pharyngeal esterase (TPE) retained 75% of its maximum activity after incubation for 1h at 50 degrees C. Thermostability of the esterase was enhanced in the presence of an analogous substrate: phosphatidylcholine. TPE had a wide pH range of stability (pH 4.0-10.0). Esterase activity was compatible with the presence of organic solvents. Furthermore, the hydrolysis was found to be slightly activated by Ca(2+), but drastically reduced by Zn(2+) and Cu(2+). Phenylmethanesulphonyl fluoride (PMSF) a serine-specific inhibitor, strongly inhibited the esterase activity, whereas beta-mercaptoethanol, a thiol group inhibitor, did not show any effect on the activity. Esterase activity in the presence of organic solvents, as well as in acidic and alkaline pHs and at high temperatures makes it a good candidate for its application in non-aqueous biocatalysis.
