Treatment with Proteinase Preparations

Proteinases injected intramuscularly or through blood vessels degrade the structural proteins and, hence, proteolytic enzymes can be used to soften or tenderize meat. The enzymes are of plant or microbial origin and are used in the meat and poultry industries, while some are also used in the 

A possible assay may be based on disc gel electrophoresis of meat extracts, prepared in the presence of urea and SDS. The band intensities of the lower molecular weight collagen fragments increase in proteinase-treated meat. 

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Phenolic extraction of cell lysates is one of the oldest techniques in DNA preparation. Examples of these have been presented in Chapters 6 and 7. Single cells in suspension are lysed with a detergent, and a proteinase enzyme is used to break down the protein molecules. Non-nucleic acid components are then extracted into an organic (phenol-chloroform) solvent, leaving nucleic acids in the aqueous layer. Two volumes of isopropanol are added to the isolated aqueous phase to precipitate the high-molecular-weight nucleic acids as a white mass. These are then treated with DNase-free ribonuclease (RNase) to remove the RNA. This is followed by a second treatment with proteinase, phenol extraction, and isopropanol precipitation. After precipitation, the DNA is separated from the isopropanol by... 

Various sample preparation approaches, including microwave-assisted extraction and enzymatic digestion procedures, were examined to extract selenium from the defatted Brazil nut matrix among these approaches, enzymatic treatment with Proteinase K proved most effective [49]. SeMet was demonstrated to be the most abundant of these seleno-amino acids. In their study, another selenium species with m/z = 361 was also detected. By application of collision-induced dissociation (CID), there was evidence for this compound to be a dipeptide consisting of tyrosine and methionine with Se [49] as shown in Figure 9.1. It was proposed by the authors that this was a dipeptide with the structure p-HO(QH4)CH2CH(NH2)CONHCH(COOH)CH2CH2SeCH3. 

Cell lysis and preparation of crude DNA by high-salt extraction in the presence of CTAB and proteinase K and then by treatment with SDS... 

Enzymatic Methods. Classical enzymatic treatment (involving lysozyme, proteinases, DNAses, etc) with or without a surfactant step can be used to remove the non-PHA biomass (71). Biologists have used these methods to prepare native PHB granules to study intracellular enzymatic degradation. On a commercial... 

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