Lipases distribution

Hohe, K. A., Dimick, P. S. and Kilara, A. 1985. Milk lipoprotein lipase distribution in the major fractions of bovine milk. J. Dairy Sci. 68, 1067-1073. 

Bachman, K.C., Wilcox, C.J. 1990b. Effect of blood and high density lipoprotein preparations upon lipase distribution and spontaneous lipolysis in bovine milk. J. Dairy Sci. 73, 3393-3401. 

Sundheim, G., Bengtsson-Olivecrona, G. 1987d. Hydrolysis of bovine and caprine milk fat globules by lipoprotein lipase. Effects of heparin and of skim milk on lipase distribution and on lipolysis. J. Dairy Sci. 70, 2467-2475. 

Few studies appear to have been made of lipase distribution in whole plants, but the enzyme is present in cambium and bark (134) and in roots (135), including the horse radish (136,137). On the other hand, fairly extensive investigations have been made of lipases in plant seeds and flours prepared from them. Their activity is one of the important factors causing deterioration of seeds or flours on keeping (138). 

Although, this model describes enzyme adsorption, other studies have shown that the lipase distribution on the support surface can be presented by a Freundlich model (Knezevic et al., 1998 Mojovic et al., 1998) that describes nonidentical adsorption on the support surface, or by a Redlich-Peterson model (Al-Duri and Yong, 2000) that combines the Langmuir and Freundlich isotherms. The Langmuir model reflects irreversible adsorption and is based on the assumption that every adsorption site is identical and energetically equivalent. However, this is a condition that is rarely... 

Lipase-catalyzed intermolecular condensation of diacids with diols results in a mixture of macrocycUc lactones and liuear oligomers. Interestingly, the reaction temperature has a strong effect on the product distribution. The condensation of a,(D-diacids with a,(D-dialcohols catalyzed by Candida glindracea or Pseudomonas sp. Upases leads to macrocycUc lactones at temperatures between 55 and 75°C (91), but at lower temperatures (<45°C) the formation of oligomeric esters predorninates. Optically active trimers and pentamers can be produced at room temperature by PPL or Chromobacterium viscosum Upase-catalyzed condensation of bis (2,2,2-trichloroethyl) (+)-3-meth5ladipate and 1,6-hexanediol (92). 

Both intact carotenoids and their apolar metabolites (retinyl esters) are secreted into the lymphatic system associated with CMs. In the blood circulation, CM particles undergo lipolysis, catalyzed by a lipoprotein lipase, resulting in the formation of CM remnants that are quickly taken up by the liver. In the liver, the remnant-associated carotenoid can be either (1) metabolized into vitamin A and other metabolites, (2) stored, (3) secreted with the bile, or (4) repackaged and released with VLDL particles. In the bloodstream, VLDLs are transformed to LDLs, and then HDLs by delipidation and the carotenoids associated with the lipoprotein particles are finally distributed to extrahepatic tissues (Figure 3.2.2). Time-course studies focusing on carotenoid appearances in different lipoprotein fractions after ingestion showed that CM carotenoid levels peak early (4 to 8 hr) whereas LDL and HDL carotenoid levels reach peaks later (16 to 24 hr). 

An alternative method is interesterification where the fatty acids are rearranged. This can be done chemically, which gives a random distribution, or by using enzymes. The advantage of enzymes is that they are very specific in their action. It is quite possible using a lipase to remove... 

Sandholzer, C., Feussner, G., Brunzell, J., and Utermann, G., Distribution of apolipopro-tein(a) in the plasma from patients with lipoprotein lipase deficiency and with type III hyperlipoproteinemia. J. Clin. Invest. 90, 1958-1965 (1992). 

Hydrolysis of Copolyamide-esters (CPAEs) by Lipase (jj,). CPAEs were synthesized by the amide-ester interchange reaction between polyamide and polyester. The length of the polyamide blocks was measured after hydrolysis of ester bonds in CPAE by alkali at 30 C. The infrared spectra after hydrolyzing ester bonds on CPAEs showed that the ester bonds were almost completely removed. The molecular weight distribution of polyamide blocks was examined by GPC (Table II). The following samples were used CPAE-1 (reaction time for synthesis, 1 hr) and CPAE-2 (reaction time, U hr) composed of nylon 6 and PCL at a 50/50 molar ratio, CPAE-3 (reaction time, 1 hr) and CPAE-U (reaction time,... 

So it was assumed that the amount and distribution of hydrogen bonds, based on the amide bonds, in the CPAE chains influenced their biodegradability by this lipase. 

The use of MALDI-MS for the measurement of low molecular mass compounds is widely accepted now [61], but quantification remains problematic. The main problem is the inhomogeneous distribution of the analytes within the matrix [62]. This leads to different amounts of ions and therefore to different signal intensities at various locations of a sample spot. The simplest and most effective way to overcome this problem is the use of an appropriate internal standard [63]. The use of deuterated compounds with a high molecular similarity to the analyte as internal standards leads to a linear correlation between relative signal intensities and relative amount of the compound to be quantified (Fig. 4b) [64]. Using this approach it is possible to quantitate substrates and products of enzyme catalyzed reactions. Two examples were shown recently by Kang and coworkers [64, 65]. The first was a lipase catalyzed reaction which produces 2-methoxy-N-[(lR)-l-phenylethyl]-acetamide (MET) using rac-a-... 

Fig. 5.2.1 The major metabolic pathways of the lipoprotein metabolism are shown. Chylomicrons (Chylo) are secreted from the intestine and are metabolized by lipoprotein lipase (LPL) before the remnants are taken up by the liver. The liver secretes very-low-density lipoproteins (VLDL) to distribute lipids to the periphery. These VLDL are hydrolyzed by LPL and hepatic lipase (HL) to result in intermediate-density lipoproteins (IDL) and low-density lipoproteins (LDL), respectively, which then is cleared from the blood by the LDL receptor (LDLR). The liver and the intestine secrete apolipoprotein AI, which forms pre-jS-high-density lipoproteins (pre-jl-HDL) in blood. These pre-/ -HDL accept phospholipids and cholesterol from hepatic and peripheral cells through the activity of the ATP binding cassette transporter Al. Subsequent cholesterol esterification by lecithinxholesterol acyltransferase (LCAT) and transfer of phospholipids by phospholipid transfer protein (PLTP) transform the nascent discoidal high-density lipoproteins (HDL disc) into a spherical particle and increase the size to HDL2. For the elimination of cholesterol from HDL, two possible pathways exist (1) direct hepatic uptake of lipids through scavenger receptor B1 (SR-BI) and HL, and (2) cholesteryl ester transfer protein (CfiTP)-mediated transfer of cholesterol-esters from HDL2 to chylomicrons, and VLDL and hepatic uptake of the lipids via the LDLR pathway...

Figure 8.15 Cartoon showing how proteins, polysaccharides and surfactants (emulsifiers) might be distributed at the triglyceride-water interface. Inter-facial complexation in vivo between adsorbed protein and charged polysaccharide in the gastrointestinal tract could affect digestion of protein and fat by forming structures that inhibit the accessibility and activity of enzymes (proteases and lipases). Reproduced from Dickinson (2008) with permission.

Gaffney, P. J., Jr. and Harper, W. J. 1966. Distribution of lipase among components of a water extract of rennet casein. J. Dairy Sci. 49, 921-924. 

Wang, L. and Randolph, H. E. 1978. Activation of lipolysis. I. Distribution of lipase activity in temperature activated milk. J. Dairy Sci. 61, 874-880. 

Modern photovoltaic infrared cameras can detect heat in the form of IR radiation from objects. The picture obtained thereby provides a two-dimensional thermal image that is a spatial map of the temperature and emissivity distribution of all objects in the picture. The technique was used to test the activity of heterogeneous catalysts [40] and thereafter to detect enantioselective lipases on microtiter plates [30,31]- The method is useful for identifying highly enantioselective hits. However, because quantification has not yet been achieved, the assay cannot readily be used to detect small differences in enantioselectivity. 

Paradis E., Clavel S., Julien P., Murthy M. R. V., de Bilbao F., Arsenijevic D., Giannakopoulos P., Vallet P., and Richard D. (2004). Lipoprotein lipase and endothelial lipase expression in mouse brain regional distribution and selective induction following kainic acid-induced lesion and focal cerebral ischemia. Neurobiol. Dis. 15 312-325. 

The enzymes responsible for the platelet metabolism are distributed in different platelet structures, For example, the plasma membrane contains adenylate cyclase in contrast, phospholipase (PL) A2, diglycerol lipase, cyclooxygenase... 

The technology also represents a suitable strategy for the preparation of multiphase reaction systems that use phase transfer (bio)catalysts. Giorno et al. [88] reported on the use of membrane emulsification to distribute lipase from Candida rugosa at the interface of stable oil-in-water emulsions. The enzyme itself was used as a surfactant. Shirasu Porous Glassy (SPG) membranes having a nominal pore... 

Fig. 1. Pore size distributions (dV/d Log [D]) of pure silica gel (PS), silanized and activated silica (SPS), and immobilized derivatives in silica gels (ADS, silica with lipase physically adsorbed CB1, silica with lipase covalently bonded CB2, silica with lipase covalently bonded in the presence of PEG EN1, silica with entrapped lipase EN2, silica with lipase entrapped in presence of PEG).

Enzymatic polymerization of lactones is a promising approach and has been investigated by several workers [45,46,71-78]. Poly(e-CL) with Mn=14,500 and a molecular weight distribution of 1.23 has recently been reported using Pseudomonas sp. lipase as the catalyst [71]. A complex mechanism involving both ring-opening and linear condensation polymerizations has been proposed for the enzymatic polymerization of lactones. 

This method permits a clear distinction between a natural olive oil and an olive oil that has undergone esterification or inter-esterification processes, by determining the distribution of fatty acids on the three positions of glycerol. Lipases catalyse the following reactions ... 

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