Enzymic activity, effect formaldehyde

Undesirable deactivation may be caused by high temperature and time, for example, caused by transport and storage and also by enzyme poisons such as certain surfactants (especially cationic ones), formaldehyde-containing products or heavy metal ions. An activation effect on cellulases was reported by Nicolai and co-workers. Alkaline pretreatment, low concentrations of selected non-ionic surfactants, polycarboxylic acids and polyvinyl pyrrolidone can enhance the bio-fmishing of cellulosics. 

The ability of respiratory and olfactory tissues to oxidize formaldehyde was examined in male Fischer 344 rats. To determine the effects of repeated formaldehyde exposure on enzyme activities, rats were exposed to 15 ppm formaldehyde 6 hours/day for 10 days. At the completion of formaldehyde exposure, rats were sacrificed and respiratory and olfactory mucosal tissues were harvested. The enzymatic capacity of the tissues was determined in the presence and absence of glutathione. Tissue homogenates from both the respiratory and olfactory mucosae demonstrated the ability to oxidize formaldehyde the oxidation of formaldehyde occurred at similar rates in the respiratory and olfactory mucosal homogenates (Casanova-Schmitz et al. 1984b). 

Since disturbed acid phosphatase activity has been associated with pathological conditions, the research has focused on the development of diagnostic methods for detection of activity as a marker for the onset of the disease, and in some extent to the development of inhibitors rather than activators to treat those conditions in which the increase in enzyme activity has a direct effect on the evolution of the disease. In particular, only the development of bisphospho-nate derivatives as inhibitors for tartrate-resistant acid phosphatase found their way to the market for treatment of osteoporosis [41], Typical inhibition of phosphatase activity includes anionic species such as L-(+)-tartrate, phosphate, vanadate, molybdate, and fluoride and neutral molecules such as formaldehyde. Vanadate ion,, is a competitive unspecific inhibitor for acid phosphatases by forming transition state analogs. Other oxoanions such as molybdate and tungstate also show inhibitory effects on... 

Some enzymes and enzyme systems are still active at the temperature of frozen storage (123-132). Such enzymatic activity, especially of proteases, may cause loss of biological activity of actomyosin and other muscle proteins. Products of such enzymatic activity, e.g. free fatty acids and formaldehyde, may effect a secondary denaturation of muscle proteins. 

Abul-Fadl and King (Al, A2, A3, A4) also investigated the effect of various ions and organic compounds on the acid phosphatase activity of these two tissues. Without describing the results in detail, some of the outstanding effects may be noted. A concentration of 0.5 X 10 M Cu inhibited erythrocytic phosphatase to the extent of 88-96%, but prostatic phosphatase only to the extent of 10-18%. Similarly, 0.5% formaldehyde inhibited completely the erythrocytic phosphatase, but had no effect on prostatic phosphatase. The reverse patterns were shown by 0.5 X 10 M Fe + (ferric) ion, which inhibited erythrocytic phosphatase slightly, about 5-9%, and inhibited the prostatic enzyme to the extent of 80%. Fluoride in 0.01 Af concentration also had comparatively little effect (8% inhibition) on erythrocytic phosphatase but exerted a marked inhibition, 96%, on prostatic phosphate. Of various organic radicals tested, only L-( + )-tartrate (0.01 A/) had a marked differential effect, with 94% inhibition of the prostatic phosphatase and none of the erythrocytic phosphatase. 

The activity of EtO, similar to many other disinfectants, preservative, and sterilizing agents, such as formaldehyde, beta-propiolactone, methylbromide, and ethylenimine, depends on an alkylation reaction. This reaction occurs with some groups within the complex enzymes, proteins, and nucleic acids in the bacterial cell. These compounds can then no longer be effective or necessary to the vital processes of the microorganism cell. Furthermore, one would expect these effects to vary according to the extensions of reactions static, mutagenic, or toxic. 

The effects of diffusion control on the rate of radiation-initiated graft polymerization of cellulose have been studied theoretically. The effects of such variables as the initiator concentration, temperature, and monomer polymer ratio on the graft copolymerization of acrylamide and 0-methylcellulose have been investigated. The thermal properties and behaviour of graft copolymers of formaldehyde-cross-linked 0-cyanoethylcellulose and acrylates have been studied. Copolymerization of periodate-oxidized cellulose (aldehydocellulose) with glycidyl methacrylate in the presence of an enzyme e. peroxidase) afforded a means of immobilizing the enzyme without loss of activity. ... 

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