[A modification of lactoferrin isolation method].

A modified method was developed to isolate lactoferrin from women's colostrum by means of ion-exchange chromatography on a Servacel CM-52 column and gel filtration on a Toyoperal HW-52 column. These changes simplified the basic method and decreased the length of the procedure without affecting the biological activity and purity of the preparation. The modified method can be recommended to produce lactoferrin suitable for the use as a pharmaceutical preparation and nutritional additive to milk substitutes.

[Cardiolipin antibodies in pregnancy of high risk].

Cardiolipin IgG and IgM antibodies (CAb) were studied in 116 cases of high-risk pregnancy. All the women were undergoing examination or treatment in regional perinatal center. CAb occurred more frequently in antenatal fetal death (50%).

[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.

[Non-enzymatic deamidation and autofragmentation of lysozyme and albumin under physiological conditions].

Nonenzymic deamidation of amides in proteins (lysozyme and albumin) under conditions which imitate physiological ones has been experimentally established with subsequent asparagine-dependent autofragmentation of the polypeptide chain.

[Amidation of blood proteins during hyperglycemia in experimental diabetes mellitus].

Rates of amidation of blood serum albumin and hemoglobin was studied in hyperglycemia developed during alloxan diabetes mellitus. Content of glucose in blood of the animals with diabetes exceeded 5.2-fold its level in blood of controls; amount of glycosylated hemoglobin was increased by 41.

[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.

[Changes in the fluorescence in preparations of normal human immunoglobulin during deamidation].

It was shown that self-fluorescence of normal human immunoglobulins prepared with the use of donor and placental raw materials lowered after incubation at 37 degrees C for 28 days and after storage under the standard conditions (4-10 degrees C) for 2 years. Dependence of thermostability of the immunoglobulins on the raw material used for their preparation and the storage period was revealed spectrofluorometrically. Resistance of the proteins to thermal denaturation lowered on storage.

[The effect of various chemical compounds and storage conditions on the rate of non-enzymatic deamidation of protein preparations].

The effect of different substances partly used as preservatives for the blood storage and at different stages of manufacturing of human blood preparations on the dynamics of nonenzymatic deamidation of commercial protein preparations and on their heat stability was being studied. Albumin and gamma-globulin preparations in the solutions of 60% glycerol, 60% ethylene glycol, 40% beta-alanine, aspartic and glutamic acids in physiological concentrations, 40% glucose and 40% sucrose after 2-hour thermal denaturation (100 degrees) were incubated under (or close to) physiological conditions (pH 7, 37 degrees) for 0.7; 14, 21, 28 and 90 days.

[Effect of non-enzymatic desamidation of gamma-globulin on its properties and biological activity].

During incubation of gamma-globulin preparations under conditions similar to physiological ones within 28 days (0.9% NaCl, pH 7.0, 37 degrees) as well as during storage at 3-10 degrees within 36 months gradual nonenzymatic deamidation of the protein occurred mainly due to hydrolysis of readily accessible amide groups (asparagine).

[Degradation of deamidated proteins by tissue proteinases].

The rate of native and deamidized serum albumin in vitro splitting by the brain, liver, kidney, testicle and spleen tissue proteinases was studied at pH 3.2, 4.8, 7.

[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.

[Protein amidation in the aging organism].

The role of protein amide groups was studied in the process of the organism ageing. It is shown that with ageing there occurs the asparagin deamidation in water-soluble and water-insolbule proteins of the rat brain, liver and heart. The glutamine content in the old rat tissues remains at the level determined in the young animal tissues.

[Spontaneous deamidation of gamma-globulin].

gamma-Globulin from human blood serum was incubated in thermostat at 37 degrees within 15, 30, 45, 60 and 72 days. Amount of readily and poorly hydrolyzed amide groups as well as an increase in amino acid content were estimated in the protein at zero time and at these periods. The sterility of the preparation was examined in each case.

[Nonenzymatic deamidation as a factor in protein aging].

Amidation of two protein fractions of brain, heart and liver of senite rats was found to decrease by 15--21% as compared with that of young animals. This decrease was shown to be due to unstable amide groups. Strong evidence is presented favouring the preposition that in proteins the unstable amide groups are those of asparagine and the stable ones those of glutamine.