Protein matrix disruption

Another way to get around the diffusional limitations of whole kernel steeping is to hydrate the corn using pressure.257,258 While pressure hydration accelerates the rate of water uptake, steeping involves more than water hydration (in conventional wetmilling hydration occurs primarily during the first 12 hours). Pressure hydration must be used in conjunction with some method to disrupt the protein matrix. The major... 

The cornified cell envelope is the outermost layer of a corneocyte, and mainly consists of tightly bundled keratin filaments aligned parallel to the main face of the corneocyte. The envelope consists of both protein and lipid components in that the lipid is attached covalently to the protein envelope. The envelope lies adjacent to the interior surface of the plasma membrane. " The corneocyte protein envelope appears to play an important role in the structural assembly of the intercellular lipid lamellae of the stratum corneum. The corneocyte possesses a chemically bound lipid envelope comprised of A-co-hydroxyceramides, which are ester linked to the numerous glutamate side chains provided possibly by both the ot-helical conformation and p-sheet conformation of involucrin in the envelope protein matrix. In the absence of A-oo-hydro-xyceramides, the stratum corneum intercellular lipid lamellae were abnormal and permeability barrier function was disrupted. 

The analysis of heterologous proteins in recombinant hosts, such as E. coll, presents many challenges to the analytical biochemist. The cells must be lysed and the inclusion bodies solubilized prior to quantification. Cell lysis and protein solubilization can be accomplished chemically through the use of SDS. As the proteins in inclusion bodies can exist as a distribution of forms, such as covalent and noncovalent polymers, it is crucial to convert the target protein into a single molecular entity prior to analysis. This can be achieved by unfolding the proteins and disrupting the inter- and intramolecular disulfide bonds via reduction or sulfitolysis. The complexity of the matrix adds to the difficulty in the determination of the recombinant protein, as both the whole cell and the inclusion bodies can also contain nucleic acids, salts, lipids, and other host molecules, in addition to proteinaceous material. 

Holt and Cotton concluded that a careful purification of GOx results in extremely weak and, under some circumstances, undetectable SERRS spectra at a silver electrode [56, 57]. GOx shows a gradual disruption of the protein matrix on the electrode surface as Flavin adenine dinucleotide (FAD) is released from the GOx molecule onto the electrode surface and denaturation of the GOx structure allows direct contact between FAD and the electrode surface. The flavoproteins suffer loss of flavin upon contact with SERS active silver surfaces in all cases... 

The absorption efficiency of the different carotenoids is variable. For example, (3-cryptoxanthin has been reported to have higher absorption efficiency than a-cryptoxanthin in rats (Breithaupt and others 2007). Carotenoids must be liberated from the food before they can be absorbed by intestinal cells (Faulks and Southon 2005). Mechanical disruption of the food by mastication, ingestion, and mixing leads to carotenoid liberation (Guyton and Hall 2001). The enzymatic and acid-mediated hydrolysis of carbohydrates, lipids, and proteins (chemical breaking of the food) also contributes to carotenoids liberation from the food matrix (Faulks and Southon 2005). Once released, carotenoids must be dissolved in oil droplets, which are emulsified with the aqueous components of the chyme. When these oil droplets are mixed with bile in the small intestine, their size is reduced, facilitating the hydrolytic processing of lipids by the pancreatic enzymes (Pasquier and others 1996 Furr and Clark 1997 ... 

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