Structural study of AOT reverse micelles containing native or modified proteins: influence of surfactant-enzyme interaction

Pileni, Marie‐Paule; Cassin, G.; Michel, François; Pitre, Franck

doi:10.1016/0927-7765(94)01142-r

Cited by 9 publications

(12 citation statements)

References 36 publications

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“…This reduction is probably related to an induction of attractive interactions within the droplets due to the participation of the protein at the interface or, to a minor extent, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 15 due to the presence of the lipase in the micelle center 21,22 . At higher w 0 value the enzyme seems not to interfere with the system and the polydispersity was reduced when compared with the empty ones.…”

Section: Dynamic Light Scatteringmentioning

confidence: 97%

“…In this case, the effect of protein incorporation at low water content (w 0 5 and 8) could lead to aggregation between two or more empty droplets (system with buffer, but without protein) to accommodate an enzyme [20][21][22] . This condition would support the longer decay times observed in the autocorrelation functions in comparison to the other w 0 values ( Figure S1, B and C).…”

Section: Dynamic Light Scatteringmentioning

confidence: 99%

“…As observed in Table 2, the Rg of the systems increased upon water addition. In the cases of w 0 5 and 8, there was no significant change between Rg obtained for empty and loaded with enzymes micelles, which could be 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 22 explained by the equilibrium between droplets with and without protein that could happen after the combination of n droplets to accommodate the protein [20][21][22] .…”

Section: Small Angle X-ray Scattering (Saxs)mentioning

confidence: 99%

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Nanoencapsulated Lecitase Ultra and Thermomyces lanuginosus Lipase, a Comparative Structural Study

et al. 2016

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Two commercially available and widely used enzymes, the parent Thermomyces lanuginosus lipase (TLL) and the shuffled phospholipase A1 Lecitase (Lecitase Ultra), were encapsulated in AOT/isooctane reverse micelles and evaluated regarding their structure and activity. Preparations were also tested as effective biocatalysts. Small-angle X-ray scattering (SAXS), electronic paramagnetic resonance (EPR), and fluorescence spectroscopy were the techniques applied to assess the effects of enzyme incorporation to a reverse micellar nanostructure. SAXS analysis showed that the radius of gyration (Rg) changed from 16 to 38 Å, as the water content (w0) increased. Elongated shapes were more commonly observed than spherical shapes after enzyme encapsulation. EPR studies indicated that enzymes do not participate in the interface, being located in the aqueous center. Fluorescence energy transfer showed that TLL is located in the water core, whereas Lecitase Ultra is closer to the interface. Enzymatic activity toward a standard esterification reaction endured after the enzyme was incorporated into the micelles. The activity of TLL for systems with w0 15 showed the highest conversion yield, 38% in 2 h, while the system with w0 10 showed the highest initial velocity, 0.43 μM/min. This last system had a Rg of 19.3 Å, similar to that of the TLL monomer. Lecitase Ultra showed the highest conversion yields in systems with w0 10, 55% in 2 h. However, the initial rate was much lower than that of TLL, suggesting less affinity for the substrates, which is expected since Lecitase Ultra is a phospholipase. In summary, we here used several spectroscopic and scattering techniques to reveal the shape and stability of TTL and Lecitase Ultra encapsulated systems, which allowed the selection of w0 values to provide optimized enzymatic activity.

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Section: Dynamic Light Scatteringmentioning

confidence: 97%

Section: Dynamic Light Scatteringmentioning

confidence: 99%

Section: Small Angle X-ray Scattering (Saxs)mentioning

confidence: 99%

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Nanoencapsulated Lecitase Ultra and Thermomyces lanuginosus Lipase, a Comparative Structural Study

et al. 2016

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“…As for the size of the micelles, the literature reports somewhat contradictory results. Pileni and co-workers suggested a model [5,9,14,15] according to which hydrophilic proteins such as α-chymotrypsin and ribonuclease tend to be located in the water core, avoiding contact with the surfactant head groups. This localization causes an equivalent increase in the water core volume and therefore increased radii.…”

Section: Introductionmentioning

confidence: 99%

“…Several groups have investigated the process of protein incorporation into reversed micelles in terms of the driving forces for protein solubilization, protein localization, and size or shape perturbations induced by the protein [3][4][5][6][7][8][9][10][11][12][13][14][15]. Additionally, the structure of the protein, which is crucial if an enzymatic reaction is to be carried out using reverse micellar system, has been examined.…”

Section: Introductionmentioning

confidence: 99%