Storage of enzymes

One limitation of enzyme replacement therapy is the targeting of enzyme proteins to appropriate sites of substrate accumulation. Administration of a cholesterol esterase conjugated to albumin results in the degradation of pathologic cholesterol ester accumulations within the lysosomes of fibroblasts from a patient with cholesterol ester storage disease (246). 

There are important methodologic considerations which apply to the use of cultured amniotic fluid cells for the detection of biochemical disorders. The first is that the enzymes which can be sampled are those which are usually present in fibroblasts or fibroblast-like cells. Therefore, conditions such as phenylketonuria and glycogen storage disease type I, which are associated with deficiencies of enzymes present only in liver and kidney, are not amenable to this approach. The same also pertains to enzyme deficiencies affecting other specific tissues. 

Enzymatic maceration, which is a softening of plant tissue by the use of enzymes, has some potential quality advantages over mechanical-thermal disintegration as maceration is obtained with less damage to the cell walls. The major part of the plant cells remains intact by enzymatic maceration [25], as the enzymes attack only the space between the cells, and with only rare injury to the cell membrane [26]. The intact cells protect nutritional components within the cells which minimise flavour changes and deterioration on storage [27,28]. 

The 4 g of iron in the human body is normally com-partmented into its functional locations in the haem- and non-haem-containing, and iron-binding proteins and enzymes (Fig. 3.5). The majority (65%) of the iron is in the divalent state in haemoglobin and myoglobin, which are involved in the transport and storage of oxygen in erythrocytes and myocytes, respectively. The remainder is distributed between storage sites, predominantly in the... 

The term pharmacodynamics encompasses all the processes that influence the relationship between drug concentration and resulting effects. Psychotropic drugs have a wide variety of targets within neuro transmitter systems, including neurotransmitter synthesis, degradation of enzymes, storage, receptors, and specific transporter proteins. 

The recruitment of zinc for a structural role, or to activate an enzyme, has been observed. The zinc ion induces the dimerization of human growth hormone (hGH), with two Zn ions associated per dimer of hGH. This is confirmed by replacement of possible zinc binding residues resulting in weakened binding of the zinc ion. Formation of a zinc-hGH dimeric complex may be important for storage of hGH in secretory granules.975 In a toxic role, anthrax lethal factor is one of the three components of the secreted toxin and is a zinc-dependent protease that cleaves a protein kinase and causes lysis of macrophages.976... 

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