[Fluorometric determination of amide protein groups].

A new fluorometric method for detection of amide protein groups is proposed. The method has a number of advantages over the routine phenol hypochlorite method, this permitting its wider application in clinical and laboratory practice. The suggested method may be used for direct detection of ammonium in biological samples.

[Use of proteolytic enzyme inhibitors for stabilizing medicinal substances during storage].

The possibility of stabilizing medicinal preparations of protein nature using the inhibitor of proteolytic enzymes, contrical (Trasilol) has been studied. On long storage, free ammonia and products of protein fragmentation accumulated in protein preparations, and the degree of amidation was reduced. This led to the decrease in biological activity of immunoglobulins and insulin.

[Effect of starvation on the intensity of proteolysis and amidation of proteins in tissues of rats of different ages].

Rates of autolysis and degree of amidation of tissue proteins were studied in rats under conditions of ageing and after starvation during 7 days. Proteins with decreased content of amide groups accumulated in brain, liver tissues and skeletal muscles. This phenomenon occurred apparently due to decrease in the rate of protein autolysis observed in ageing.

[Effect of glutathione on the proteolytic degradation of tissue proteins in young and old rats].

The proteolysis rate of the total liver, brain and testicle homogenates from young and old rats was studied by proteolytic enzymes. The level of autolytic destruction of brain and liver proteins decreases with aging. The total liver, brain and testicle proteins of young animals are splitted by pronase faster than the proteins of the old ones.

[Effect of extreme exposure on the intensity of autolysis in the brain and liver of rats].

Stress caused by 3-hour cold exposure of the animals (2-4 degrees C) or 7-day starvation is accompanied by the increase of protein autolysis in liver by 21%. At that the intensity of the autolysis in brain leaves unchanged. In spite of the same changes of the autolysis intensity in brain and in liver in cold-exposed and starved animals, the level of pholinpositive compounds in liver and brain of these two groups of animals changes in different ways in comparison with the control one.

[Posttranslational deamidation of crystalline lens proteins during animal aging].

The amide content of total proteins and protein fractions (alpha-, beta-, gamma-cristallins and albuminoid) from cortex and nuclear lens zones of cattle has been investigated. The amide content in proteins of cortex and nuclear lens of young animals (1,5-2 years old) is the same. The decrease of the amide content in the proteins of nuclear lenz zone of old animals (6-12 years old) is due to fraction of readily hydrolysed amides.

[Proteolytic splitting of proteins from the cortex and nuclear zones of the crystalline lens].

The proteolytic attacking capacity by pronase, a proteolytic wide-range enzyme, has been studied in soluble and insoluble proteins from the cortex and nuclear lens zones of young (aged 1.5-2 years) and old (aged 6-12 years) animals. It is established that proteolysis stability of proteins from the cortex lens zone in young and old animals is the same.