Cells enzymic activity

Hereditary deficiency of phosphoglycerate kinase (PGK) is associated with hereditary hemolytic anemia and often with central nervous system dysfunction and/or myopathy. The first case, reported by Kraus et al. (K24), is a heterozygous female, and the results are not so clear. The second family, reported by Valentine et al. (V3), is a large Chinese family, whose pedigree study indicates that PGK deficiency is compatible with X-linked inheritance. To date, 22 families have been reported (04, T25, Y3). Nine of these have manifested both symptoms five have shown only hemolysis seven have shown the central nervous system dysfunction and/or myopathy but without hemolysis and one case, PGK Munchen, is without clinical symptoms (F5). PGK II is an electrophoretic variant found in New Guinea populations (Y2). Red blood cell enzyme activity, specific activity, and the kinetic properties of this polymorphic variant are normal. 

Hereditary Nonhematologic Disorders That Can Be Diagnosed by the Determination of Red Blood Cell Enzyme Activity... 

Red blood cell enzyme activities are measured mainly to diagnose hereditary nonspherocytic hemolytic anemia associated with enzyme anomalies. At least 15 enzyme anomalies associated with hereditary hemolytic anemia have been reported. Some nonhematologic diseases can also be diagnosed by the measurement of red blood cell enzyme activities in the case in which enzymes of red blood cells and the other organs are under the same genetic control. 

However, any compound, even if it is chemically inert, if present at high enough concentrations in biological membranes can change those membranes properties and disrupt their functions. Consequently, membrane-associated processes like photosynthesis, energy transduction, transport in or out of the cell, enzyme activities, transmission of nerve impulses, and so on may deteriorate (see van Wezel and Opperhuizen, 1995 and literature cited therein). Since these effects seem to be primarily dependent on the space that contaminating molecules occupy in the... 

The scheme in Figure 5.1 can be used to illustrate this point. While this scheme shows three separate starting points, it also shows potential end points. For example, if the sample is multicellular, the purification could be ended after the removal of the extracellular matrix or the medium or broth used to culture cells. Enzyme activities can be measured directly in the multicellular structures or in the extracellular compartment. 

Red blood cell enzyme activity returns at the rate of red blood cell turnover, which is 1 % per day. Tissue and plasma activities return with synthesis of new enzymes. The rates of return of these enzymes are not identical. However, the nerve agent can be removed from the enzymes. This removal is called reactivation, which can be accomplished therapeutically by the use of oximes prior to aging. Aging is the biochemical... 

Red blood cell enzyme activity returns at the rate of red blood cell turnover, which is 1% per day. Tissue and plasma activities return with synthesis of new enzymes. The rates of return of these enzymes... 

In a similar experiment published only in abstract form, mammary myoepithelial cells in tissue culture were exposed to varying concentrations of A-carrageenan (molecular weight not stated) for varying durations (not detailed) to determine the effects on steroid sulfatase in the cells. Enzyme activity of steroid sulfatase and messenger RNA (mRNA) expression were determined and compared... 

The kinetics of galactosidase induction are simple [102,103] on addition of excess inducer to growing cells, enzyme activity increases at a rate proportional to the increase in total protein within the culture. Enzyme formation reaches its maximum rate at 37°C within 3 minutes of addition of inducer. After removal of inducer, enzyme synthesis ceases in about the same amount of time. 

A review [51] of early studies draws the following observations (a) strong binding of glutaraldehyde to outer cell layers, (b) the prevention of lysis by sodium lauryl sulphate ( . coli), lysostaphin (S. aureus) and EDTA-tris-lyso-zyme (P. aeruginosa), (c) the inhibition of sphaeroplast lysis in hypotonic media, (d) the inhibition of RNA, DNA and protein synthesis, and (e) the inhibition of cell enzyme activity by low concentrations [49]. 

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