Features of the acid protease partition in aqueous two-phase systems of polyethylene glycol–phosphate: Chymosin and pepsin

Spelzini, Darío; Farruggia, Beatriz; Picó, Guillermo

doi:10.1016/j.jchromb.2005.04.007

Cited by 48 publications

(43 citation statements)

References 16 publications

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“…2). Spelzini et al (2005) reported that among acid proteases, the aspartic types present molecular masses from 32 to 39 kDa. However, acid proteases characterized as aspartic-type of higher than these range have been found in other species such as 47.6 kDa from Aspergillus oryze (Vishwanatha et al 2009), 45 kDa from Neosartorya fischeri var.…”

Section: Resultsmentioning

confidence: 99%

Purification and some properties of an extracellular acid protease from Aspergillus clavatus

Silva

Knob²,

Tremacoldi

et al. 2011

World J Microbiol Biotechnol

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Acid proteases represent an important group of enzymes, widely used in food, beverage and pharmaceutical industries. For most of these applications the enzymatic preparation must be at least partially purified and free of substances that could change the characteristics of the product or the process. Fungal proteases have replaced other sources because they are easily obtained mainly from Mucor, Rhizopus, Penicillium and Aspergillus species. A strain of Aspergillus clavatus was selected by producing high level of acid protease activity. An extracellular aspartatic protease from this strain was purified 37.2 times with 37% recovery using (NH 4 ) 2 SO 4 fractionation and ionexchange chromatography. The enzyme was found to be monomeric having a molecular mass of 30.4 kDa. The purified enzyme is an acid protease with optimum pH of 5.5 and temperature for optimum activity of 50°C. Its high pH stability was verified in the range of 3.5-6.5. The acid protease was strongly inhibited by Hg ?2 and partially inhibited by Cu ?2 , Zn ?2 and Mn ?2 . The enzyme was sensitive to denaturing agent SDS and activated by thiolcontaining reducing agent dithiotreitol (DTT). The protease activity was not influenced by iodoacetic acid, E-64 and PMSF, while it was lightly actived by EDTA and totally inhibited by pepstatin, with a K i of 7.8 lM, indicating that is an aspartic protease. A. clavatus acid protease presents interesting characteristics for biotechnological process, such as cheese and flavor manufacture and dietary supplements, in which activity and stability in acid pH are required.

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Section: Resultsmentioning

confidence: 99%

Purification and some properties of an extracellular acid protease from Aspergillus clavatus

Silva

Knob²,

Tremacoldi

et al. 2011

World J Microbiol Biotechnol

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“…Precipitation at the interphase was observed since the protein saturation point in the polymer phase had reached. Moreover, an increase in the chain length of PEG will also cause reduction of available free volume (excluded volume) to accommodate lipase in the upper phase [24,25]. Another tendency that affects the partitioning, is the high PEG molecular mass which will strengthen the viscosity of system and thus unsuitable for processing.…”

Section: Effect Of Peg Molecular Weight and Tll On Lipase Partitioningmentioning

confidence: 99%

Direct purification of Burkholderia Pseudomallei lipase from fermentation broth using aqueous two-phase systems

Ooi

Tey

Hii

et al. 2009

Biotechnol Bioproc E

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An aqueous two-phase purification process was employed for the recovery of _ìêâÜçäÇÉêá~=éëÉìÇçã~ääÉá=lipase from fermentation broth. The partition behavior of _K=éëÉìÇçã~ääÉá=lipase was investigated with various parameters such as phase composition, tie-line length (TLL), volume ratio (V R ), sample loading, system pH, and addition of neutral salts. Optimum conditions for the purification of lipase were obtained in polyethylene glycol (PEG) 6000-potassium phosphate system using TLL of 42.2% (w/w), with V R of 2.70, and 1% (w/w) NaCl addition at pH 7 for 20% (w/w) crude load. Based on this system, the purification factor of lipase was enhanced to 12.42 fold, with a high yield of 93%. Hence, the simplicity and effectiveness of aqueous two-phase systems (ATPS) in the purification of lipase were proven in this study. © KSBB hÉóïçêÇëW=~èìÉçìë=íïçJéÜ~ëÉ=ëóëíÉãëI=äáé~ëÉI=éìêáÑáÅ~íáçåI=éçäóÉíÜóäÉåÉ=ÖäóÅçäI=êÉÅçîÉêó= = = = =

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“…The enthalpic change (ΔH 0 T ) and entropy change (ΔS 0 T ) can be calculated from the slope and intercept of the linear Eq. (2) [26]. The linear relationship between ln K and 1/T was shown in Fig.…”

Section: Effect Of Extraction Temperaturementioning

confidence: 86%

Extraction of Bovine Serum Albumin Using Reverse Micelles Formed by Hexadecyl Trimethyl Ammonium Chloride

Sun

Yang

et al. 2010

Appl Biochem Biotechnol

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The extraction of bovine serum albumin (BSA) has been investigated using reverse micelles of hexadecyl trimethyl ammonium chloride/n-octanol/isooctane. Forward extraction process parameters such as the surfactant concentration, co-solvent concentration, pH, ionic strength, and species of the initial aqueous phase were important factors affecting the extraction performance. These parameters were varied to optimize the extraction efficiency. Under the optimized conditions, forward extraction efficiencies of BSA can reach practically 99.55%. The thermodynamic study revealed that the extraction of BSA is controlled by entropy changes. Maximum back-extraction efficiency of 85.16% can be obtained at low pH values and high salt concentrations. The structures of BSA during reverse micelle extraction did not change by comparing the circular dichroism spectra of BSA back-extracted to the aqueous phase with that of feed BSA.

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Features of the acid protease partition in aqueous two-phase systems of polyethylene glycol–phosphate: Chymosin and pepsin

Cited by 48 publications

References 16 publications

Purification and some properties of an extracellular acid protease from Aspergillus clavatus

Purification and some properties of an extracellular acid protease from Aspergillus clavatus

Direct purification of Burkholderia Pseudomallei lipase from fermentation broth using aqueous two-phase systems

Extraction of Bovine Serum Albumin Using Reverse Micelles Formed by Hexadecyl Trimethyl Ammonium Chloride

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