Protein hydrolysate fatty acid

Figure 4.6 Structure of protein hydrolysate fatty acid condensates.

The optimized assay mix (500 xL) contains 1 mM NADH, 1 mM NADPH, 2 mM DTT, 10 pM acyl carrier protein (ACP), 10 fiM acetyl-CoA, 59.4 xM malonyl-CoA, 0.51 iM (2- C)-malonyl-CoA (59 mCi/mmol purchased from New England Nuclear - all other chemicals and ACP from Sigma), and 3 fig/assay of cerulenin treated protein extract. Circa 15 ng/assay of purified KAS I is appropriate to give a clear signal. The specific activity in this assay is in the range of 5 imol/min/mg. The assay reaction runs for 1 h at 37°C and the assay was linear up to 25% incorporation of the malonyl-CoA, corresponding to circa 8000 dpm. The hydrolysed fatty acids are extracted in hexane and the radioactivity is determined. ... 

Acylated Protein Hydrolysates. These surfactants are prepared by acylation of proteia hydrolysates with fatty acids or acid chlorides. The hydrolysates are variable ia composition, depending on the degree of hydrolysis. CoUagen from leather (qv) processiag is a common proteia source. Acylated proteia hydrolysates (Maypoa, by laotex Chemical Company) are mild surfactants recommended for personal-care products (see Cosmetics). 

In analogy to the well-known condensation products of fatty acids with protein hydrolysates, a patent has also been initiated for the condensation products of ether carboxylic acids and protein hydrolysates [43]. They are made by converting the ether carboxylic acids with thionyl chloride (SOCl2) to the corresponding acid chlorides followed by the condensation with a protein hydrolysate. 

In the development of the protein-fatty acid condensates it was possible to combine the renewable resources fatty acids (from vegetable oil) and protein, which can be obtained from both animal waste (leather) as well as from many plants, to construct a surfactant structure with a hydrophobic (fatty acid) and a hydrophilic (protein) part (Fig. 4.12). This was carried out by reacting protein hydrolysate with fatty acid chloride under Schotten-Baumann conditions using water as solvent. Products are obtained that have an excellent skin compatibility and, additionally, a good cleaning effect (particularly on the skin) and, in combination with other surfactants, lead to an increase in performance. For instance, even small additions of the acylated protein hydrolysate improve the skin compatibility. An... 

Once the 16-carbon atom acyl chain is formed, the thioester link between the acyl group and the 4 -phosphopante-theine of the carrier protein is hydrolysed by a thioesterase and palmitate is released. Synthesis of shorter-chain fatty acids, e.g. myristic (a C-14 carbon acid), requires a specific cytosolic thioesterase (thioesterase II) which is present in liver. It hydrolyses the thioester bond when fatty acids reach lengths of less than 16 carbon atoms. 

Acylated Protein Hydrolysates. These surfactants are prepared by acylation of protein hydrolysates with fatty acids or acid chlorides. 

The human stomach and small intestine also contain enzymes that help in the hydrolysis and break-down of proteins, first into shorter chain peptides (this is done with the aid of the enzymes pepsin and trypsin), and then hydrolysed further into individual amino acids with the help of the enzyme peptidase. Any fats in food are also hydrolysed in the stomach with the aid of lipase enzyme to form fatty acids (carboxylic acids). 

The enzymes used for this type of digestion in Analytical Chemistry are mainly hydrolytic enzymes, the catalytic effect of which is based on the insertion of water at a specific bond of the substrate. The hydrolytic enzymes used in analytical applications include lipases (which hydrolyse fats into long-chain fatty acids and glycerol) amylases (which hydrolyse starch and glycogen to maltose and to residual polysaccharides) and proteases (which attack the peptide bonds of proteins and peptides themselves). 

The two major morphological parts in the structure of wool are cuticle and cortex. The epi-cuticle of wool fibres surrounds each cuticle, it consists of approximately one-quarter fatty acid and three-quarters protein by mass. The hydrophobic epiCLiticle acts as a barrier to dyes which enter the wool fibre between cuticle cells through the highly cross-linked cell membrane complex (CMC). Enzyme from the liquor can diffuse into the interior of the fibre and hydrolyse parts of the endocuticle and proteins in the cell membrane complex, completely damaging the fibre if not controlled. In contrast, the catalytic action of enzyme on cotton is confined to the surface and the amorphous region only. 

Of course, derivatization methods can also be used for the identification of organic acids. For example, volatile fatty acids in urine and plant protein hydrolysates were esterified with phenyldiazomethane and the resulting benzyl esters were separated by glass capillary GC [254]. Janos et al. [255] described a method for the analysis of dimedone derivatives of formaldehyde and other aliphatic aldehydes on capillary columns. Phenolic amines, 3-methoxycatecholamines, indoleamines and related amines can be determined as their N,0-ethyloxycarbonyl derivatives [256]. The reaction of dithiols and certain monothiols with phenylarsine oxide was used for derivatization prior to GC [257]. Destructive GC methods for the identification of microorganisms were described in refs. 258-261. 

When, however, 13(S)-HPOD was incubated with an ammonium sulphate precipitate of defatted com germ, the resulting 12-oxo-PDA was not optically pure but a mixture of enantiomers in a ratio of 82.18 [35]. The 12-oxo-PDA obtained by incubation of 13(S)-HPOT with flaxseed extracts was found to be a racemic mixture [36]. These results may be due to low or absent allene oxide cyclase activity in the preparations used [34]. The allene oxide cyclase, a novel enzyme in the metabolism of oxygenated fatty acids was partially characterised and found to be a soluble protein with an apparent molecular weight of about 45 kDa which catalysed specifically the conversion of allene oxide into 12-oxo-PDA [34]. The allene oxide was very unstable and was rapidly hydrolysed in aqueous media into stable 12-oxo-13-hydroxy-9(z),15(z)-octadecadienoic acid (a-ketols) [34]. 

Condensation products of fatty acid halides and protein hydrolysates are produced now in a wide range as secondary surfactants for the same needs. They may be modified additionally by quatemisation to gain more cationic nature as mentioned in the previous paragraph. The number of amino acids attached varies over a wide range whereas their morphological state... 

For shampoos, shaving foams and tooth pastes, high stability and definite foam structure is one of the main factors determining the commercial value of the product. In this connection, conventional shampoos include anionics (ammonium or triethanolamine salts of alkylsulphates mixed with alkylolamides of natural fatty acids, e.g. coconut oil acids, as well as amphoteric surfactants and hydrolysed proteins. Detailed patent data on the formulations are given in [80, 110] and other reviews. 

The esterification of cholesterol in animals has attracted considerable research because of the possible involvement of cholesterol and its ester in various disease states (cf. Glomset and Norum, 1973, and Sections 12.1, 12.3 and 12.6). Cholesterol esters are formed by the action of lecithin cholesterol acyltransferase (LCAT, EC 2.3.1.43) which is particularly active in plasma (cf. Sabine, 1977, for a review of cholesterol metabolism). The reaction involves transfer of a fatty acid from position 2 of lecithin (phosphatidylcholine) to the 3-hydroxyl group of cholesterol with the formation of monoacyl-phosphatidylcholine. Although LCAT esterifies plasma cholesterol solely at the interface of high-density lipoprotein and very-low-density lipoprotein, the cholesterol esters are transferred to other lipoproteins by a particular transport protein (CETP cholesteryl ester transfer protein). Cholesteryl esters, in contrast to free cholesterol, are taken up by cells mostly via specific receptor pathways (Brown et aL, 1981), are hydrolysed by lysosomal enzymes and eventually re-esterified and stored within cells. LCAT may also participate in the movement of cholesterol out of cells by esterifying excess cholesterol in the intravascular circulation (cf. Marcel, 1982). 

In terms of the nature of processes leading to lipid accumulation during the development of atherosclerosis the mechanisms of normal uptake of lipoproteins by cells as mentioned above must be considered. Normally LDL cholesterol is taken up by cells, following its association with high-affinity cell-surface receptors, by endocytosis. It is then delivered to lysosomes within which the protein part is hydrolysed and the cholesteryl ester is hydrolysed to cholesterol and fatty acids. When sufficient cholesterol... 

Phospholipases Aj (EC 3.1.1.4) hydrolyse the fatty acyl ester bond at the sn-2 position of membrane phospholipids to yield free fatty acids such as ara-chidonic acid. Recognised isoforms include i) low molecular weight, 14 kDa proteins that are inhibited by reducing agents, require calcium for activation and exhibit no preference for the hydrolysis of arachidonic acid vs. other fatty acids ii) cytosolic, an 85 kDa protein that is resistant to reducing agents, calcium-requiring and preferentially hydrolysed arachidonic acid and iii) calcium-indepen-... 

The hydrolases catalyse hydrolytic cleavage. Typical are the hydrolyses associated with fat and protein digestion, which are essential for the normal functioning of the organism. A fat may be broken down to glycerides (acylglycerols) and fatty acids under the influence of a lipase ... 

The ability of exogenous proteins to reduce the skin and eye irritation potential of detergents was highlighted many decades ago in the cosmetic chemistry community. First extensive insights were probably those of Meinecke (4), who reported that addition of a protein hydrolysate or a protein-fatty acid condensate to a solution of a highly irritant surfactant (sodium alkylbenzene sulfonate) caused a remarkable increase in the skin tolerability of the product and postulated a protective effect based on the formation of a protein colloidal layer on the skin, which could prevent or minimize the direct interaction of tenside molecules with skin keratin. The same interpretation has been advanced more recently by other authors (116-118). 

Soluble native proteins, protein hydrolysates, and fatty acid condensates are sometimes used to improve and refine the physicochemical properties of cosmetic formulations. Many... 

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