Rabbit kidney aminopeptidases: purification and some properties

Oliveira, S. Maximiano de; Freitas, J.O.; Alves, K. B.

doi:10.1016/s0162-3109(99)00080-6

Cited by 4 publications

(3 citation statements)

References 20 publications

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“…Aminopeptidase activity was also evaluated using aminoacyl b-naphthylamide (AA-NA) with the following substrates: Arg, Leu, Phe, Val and Lys. The procedure adapted from Oliveira, Freitas Jr and Alves (1999) was carried out by incubating 4.2 mM substrate (50 mL), 50 mM sodium phosphate bu¡er, pH 7.0, (600 mL) and dionized H 2 O (50 mL) at 37 1C. After temperature equilibration, the enzyme extract (50 mL) was added.…”

Section: Enzyme Activity Assaysmentioning

confidence: 99%

Digestive peptidases and proteinases in the midgut gland of the pink shrimpFarfantepenaeus paulensis(Crustacea, Decapoda, Penaeidae)

Buarque

Castro

Santos

et al. 2009

Aquaculture Research

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Proteases from the midgut gland of the Farfantepenaeus paulensis juveniles were assessed. Enzyme activity was determined using protease substrates and inhibitors. The effect of pH, temperature and calcium on proteolytic activity was assayed. Caseinolytic activity was analysed in substrate‐sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Trypsin, chymotrypsin and leucine aminopeptidase activity was detected. Proteolytic activity was strongly inhibited by the specific trypsin inhibitors. Tosyl‐phenylalanine chloromethyl ketone inhibited 59.3% of chymotrypsin activity. The greatest trypsin‐like activity occurred at pH 8.0 and 45 °C. Chymotrypsin‐like activity reached maximal values at alkaline pH (7.2–9.0) and 55 °C. CaCl2 did not increase trypsin‐like activity, but rather inhibited it at concentrations of 30 (20%), 50 (30%) and 100 mM (50%). The substrate‐SDS‐PAGE zymogram revealed eight proteinase bands. Two possibly thermal‐resistant (85 °C, 30 min) chymotrypsin isoforms were found, which were inhibited by phenyl‐methyl‐sulphonyl‐fluoride. Aminopeptidase activity of enzyme extracts (Arg, Leu, Lys, Phe and Val) and the recommended concentrations of these essential amino acids in penaeid shrimp diets were positively correlated (P<0.05). Beause protein digestion involves the combined action of different enzymes, adequate knowledge of shrimp digestion and enzyme characteristics is required for the assessment of the digestive potential of different feed sources and development of in vitro digestibility protocols.

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Section: Enzyme Activity Assaysmentioning

confidence: 99%

Digestive peptidases and proteinases in the midgut gland of the pink shrimpFarfantepenaeus paulensis(Crustacea, Decapoda, Penaeidae)

Buarque

Castro

Santos

et al. 2009

Aquaculture Research

View full text Add to dashboard Cite

show abstract

“…Activity was expressed as protease mU mg −1 of protein. One unit of enzyme activity was defined as the amount of enzyme required to hydrolyze 1 μmol of β‐naphthylamide min −1 (Oliveira et al. 1999).…”

Section: Methodsmentioning

confidence: 99%

Digestive proteinases and peptidases in the hepatopancreas of the southern brown shrimp (Farfantepenaeus subtilis) in two sub-adult stages

Buarque

Castro

Santos

et al. 2009

Aquaculture Nutrition

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The aim of this study was to examine proteinases and peptidases from the hepatopancreas of two sub-adult stages of Farfantepenaeus subtilis: SAS 6 (5.93 ± 0.69 g wet weight) and SAS 13 (13.26 ± 0.60 g wet weight). Trypsin and chymotrypsin activity was higher in the extract from the SAS 6 individuals (P < 0.05). The highest activity among aminoacyl-b-naphthylamide substrates was found using alanine-, arginine-, leucine-and lysine-b-naphthylamide. There was a positive correlation between the recommended concentration of essential amino acids in penaeid shrimp feed and aminopeptidase activity in both sub-adult stages. Proteolytic activity of F. subtilis was strongly inhibited by specific trypsin inhibitors. The optimal temperature for trypsin, chymotrypsin and leucine aminopeptidase activity was between 45 and 55°C. Six and seven bands were found in caseinolytic zymograms for SAS 6 and SAS 13 respectively. All bands were inhibited by phenylmethylsulfonyl fluoride in both sub-adult stages. The use of tosyl-lysine-chloromethyl-ketone and benzamidine caused strong inhibition of the proteolytic bands. Trypsin and chymotrypsin activity was the main difference observed between the protease pattern of SAS 6 and SAS 13 F. subtilis.

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“…Aminopeptidase activity was evaluated using aminoacyl of b-naphthylamide (AA of arginine) as substrate. The procedure adapted from Oliveira et al (1999) was carried out in triplicate, by incubating 4.2 mM substrate (50 lL), 50.0 mM sodium phosphate buffer pH 7.0 (600 lL) and deionised H 2 O (50 lL) at 37°C. After temperature equilibration, intestine crude extract (50 lL) was added, and 30 min later, the reaction was stopped by adding 1 mg mL -1 fresh Garnet reagent (250 lL) in 0.2 M sodium acetate buffer pH 4.2 containing 10 % Tween 20 (v/v).…”

Section: Aminopeptidase Activitymentioning

confidence: 99%

Digestive enzyme activity in juvenile Nile tilapia (Oreochromis niloticus, L) submitted to different dietary levels of shrimp protein hydrolysate

et al. 2012

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The effect of different dietary concentrations of shrimp protein hydrolysate (SPH) on digestive enzyme activity of Nile tilapia juveniles was evaluated. SPH concentrations in diets were 0, 15, 30 and 60 g kg-1 (treatments SPH0, SPH15, SPH30 and SPH60, respectively). Hemoglobin, azocasein, BApNA (Na-benzoyl-DL-arginine-p-nitroanilide), SApNA (Suc-Ala-Ala-Pro-Phe p-nitroanilide), aminoacyl of b-naphthylamide and starch were used as substrates for enzyme activity determinations. The activity of total alkaline protease was significantly higher (P \ 0.05) in fish under SPH15 and SPH60 treatments than in the control (SPH0). However, the effect was not dosedependent. Substrate-SDS-PAGE was also performed to evaluate changes in the profile

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Rabbit kidney aminopeptidases: purification and some properties

Cited by 4 publications

References 20 publications

Digestive peptidases and proteinases in the midgut gland of the pink shrimpFarfantepenaeus paulensis(Crustacea, Decapoda, Penaeidae)

Digestive peptidases and proteinases in the midgut gland of the pink shrimpFarfantepenaeus paulensis(Crustacea, Decapoda, Penaeidae)

Digestive proteinases and peptidases in the hepatopancreas of the southern brown shrimp (Farfantepenaeus subtilis) in two sub-adult stages

Digestive enzyme activity in juvenile Nile tilapia (Oreochromis niloticus, L) submitted to different dietary levels of shrimp protein hydrolysate

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