Storage, enzyme

Variety Storage Enzyme treatment Press yield (%)... 

Major Applications High voltage capacitors,inks, 5 energetic materials, corrosion inhibitors,fertilizer, food storage, enzyme assays, detecting microorganisms,22 immunother-... 

Human amniotic cells were considered as an alternative source of enzyme replacement. They do not express HLA antigens or microglobulin and consequently are not rejected when transplanted (5) They secrete many lysosomal storage enzymes and in addition appear to express significant adenosine deaminase activity. However, very little immune function was restored in S.Y. and none at all in K.A. after enzyme replacement therapy by red cell transfusions, and it was thought unlikely that they would have provided any further benefit. All three children have... 

The extension of the useful storage life of plant and animal products beyond a few days at room temperature presents a series of complex biochemical, physical, microbial, and economic challenges. Respiratory enzyme systems and other enzymes ia these foods continue to function. Their reaction products can cause off-davors, darkening, and softening. Microbes contaminating the surface of plants or animals can grow ia cell exudates produced by bmises, peeling, or size reduction. Fresh plant and animal tissue can be contaminated by odors, dust, iasects, rodents, and microbes. 

Contraction of muscle follows an increase of Ca " in the muscle cell as a result of nerve stimulation. This initiates processes which cause the proteins myosin and actin to be drawn together making the cell shorter and thicker. The return of the Ca " to its storage site, the sarcoplasmic reticulum, by an active pump mechanism allows the contracted muscle to relax (27). Calcium ion, also a factor in the release of acetylcholine on stimulation of nerve cells, influences the permeabiUty of cell membranes activates enzymes, such as adenosine triphosphatase (ATPase), Hpase, and some proteolytic enzymes and facihtates intestinal absorption of vitamin B 2 [68-19-9] (28). 

The dopamine is then concentrated in storage vesicles via an ATP-dependent process. Here the rate-limiting step appears not to be precursor uptake, under normal conditions, but tyrosine hydroxylase activity. This is regulated by protein phosphorylation and by de novo enzyme synthesis. The enzyme requites oxygen, ferrous iron, and tetrahydrobiopterin (BH. The enzymatic conversion of the precursor to the active agent and its subsequent storage in a vesicle are energy-dependent processes. 

Arachin, the counterpart of glycinin in peanuts, consists of subunits of 60,000—70,000 mol wt which on reduction with 2-mercaptoethanol yield polypeptides of 41,000—48,000 and 21,000 mol wt (17) analogous to the behavior of glycinin. In addition to the storage proteins, oilseeds contain a variety of minor proteins, including trypsin inhibitors, hemagglutinins, and enzymes. Examples of the last are urease and Hpoxygenase in soybeans. 

Thiamine requirements vary and, with a lack of significant storage capabiHty, a constant intake is needed or deficiency can occur relatively quickly. Human recommended daily allowances (RDAs) in the United States ate based on calorie intake at the level of 0.50 mg/4184 kj (1000 kcal) for healthy individuals (Table 2). As Httle as 0.15—0.20 mg/4184 kJ will prevent deficiency signs but 0.35—0.40 mg/4184 kJ are requited to maintain near normal urinary excretion levels and associated enzyme activities. Pregnant and lactating women requite higher levels of supplementation. Other countries have set different recommended levels (1,37,38). 

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