Pronase enzyme

Figure 7.14 shows how reactor productivity (g product/g enzyme) is affected by flux and enzyme concentration, for soy protein hydrolysis performed by Pronase enzyme. Maximum productivity can be obtained by operating the reactor at the highest flux and the lowest enzyme concentration. 

The neuraminidase molecule is a homotetramer made up of four identical polypeptide chains, each of around 470 amino acids the exact number varies depending on the strain of the virus. If influenza virus is treated with the proteolytic enzyme pronase, the head of the neuraminidase, which is soluble, is cleaved off from the stalk projecting from the viral envelope. The soluble head, comprising four subunits of about 400 amino acids each, can be crystallized. 

The effects of various enzymes on the activity of HPLC fractions that inhibited 3H-PCP binding were investigated. As shown in table 1, pronase (0.5 pg/ml), carboxypeptidase A (0.1 unit/ml), and trypsin (3.0 g/ml ) markedly decreased the potency of 10 n units of PCP-like activity. No significant change in activity was. seen when fractions were incubated with alpha-chymotrypsin. 

How, exactly, retinol affects protein glycosylation is not yet known, but the formation of retinol phosphate, the D-mannosylation of retinol phosphate by GDP-Man, and the transfer of Man from D-mannosyl (retinol phosphate) to pronase-sensitive glycoconjugates are well established.5857,59 On the other hand, the formation and role of other gly-cosyl esters of retinol phosphate are still controversial.2,80 It is very probable that the D-mannosylation of retinol phosphate, and also the transfer of Man from this lipid derivative to protein, are catalyzed by enzymes different from those involved in the dolichol pathway,81-83 and this finding points to the different physiological roles of Man-P-Dol and D-mannosyl (retinol phosphate). Thus, whereas Man-P-Dol can serve to D-mannosylate dolichol diphosphate-linked oligosaccharides (see Section III), such a role has not been found for D-mannosyl (retinol phosphate).81,83... 

Although the majority of the lipids in M. laidlawii membranes appear to be in a liquid-crystalline state, the system possesses the same physical properties that many other membranes possess. The ORD is that of a red-shifted a-helix high resolution NMR does not show obvious absorption by hydrocarbon protons, and infrared spectroscopy shows no ft structure. Like erythrocyte ghosts, treatment with pronase leaves an enzyme-resistant core containing about 20% of the protein of the intact membrane (56). This residual core retains the membrane lipid and appears membranous in the electron microscope (56). Like many others, M. laidlawii membranes are solubilized by detergents and can be reconstituted by removal of detergent. Apparently all of these properties can be consistent with a structure in which the lipids are predominantly in the bilayer conformation. The spectroscopic data are therefore insufficient to reject the concept of a phospholipid bilayer structure or to... 

Alternative methods for the synthesis of peptide aldehydes include reduction of acid halides, phenyl esters, thioesters, and anhydrides prepared from corresponding acids, isoxazolidides, and the hydrolysis of thiazolidine peptides 17,54-56 Enzymes such as thermolysin, subtilisin, and pronase E have proven valuable as effective semisynthetic alternatives 40,57 5 62 ... 

Aspartame has been assayed by a flow injection analysis biosensor employing an immobilized enzyme (pronase) which cleaves the peptide bond. The resulting phenylalanine methyl ester is then detected by an L-amino acid oxidase electrode. This method was applied to analysis of aspartame in foods [82]. 

The keratin structure is destroyed through the use of proteolytic enzymes such as pronase and proteinase K. They are often used with chemical agents such as urea and thioglycolic to cleave the disulfide bonds and increase the dissolution rate of enzyme activity. The extracting procedures, using enzymatic digestion, last about 4-6 h and must be conducted at constant temperature and pH for providing maximum enzyme activity [155],... 

---