Preparation of Type II Collagen Short Peptides: Temperature Conditions of Cartilage Homogenization and Collagen Hydrolysis.

Physicochemical properties of hyaline cartilage homogenates were studied by the method of microcalorimetry. Collagen hydrolysates were obtained after homogenization of hyaline cartilages under high pressure conditions at the temperatures that denaturate collagen. Thermodynamic parameters of thermal transition of collagen in cartilage suspension were determined. Enthalpy of thermal transition ΔН decreases in comparison with the control. Thermal transition half-width ΔТ varies with temperature. More denatured and homogeneous samples were obtained at homogenization temperature 80°C. According to spectral studies, particles in the samples obtained at the temperature of 80°C were smaller. The temperature of 80°C is preferred for homogenizing hyaline cartilages and obtaining collagen type II short peptides.

Collagen Peptides from Hyaline Cartilage for the Treatment and Prevention of Joint Diseases: Isolation and Characteristics.

We studied the effects of Chymopsin and Caripazim on the proteolysis of collagen proteins from cattle tracheal hyaline cartilage. Homogenization of the cartilage under conditions of high pressure and temperature facilitated subsequent enzymatic hydrolysis: the degree of hydrolysis increased upon elevation of pressure from 40 to 80 mPa and temperature from 60 to 70°C. Proteolysis with Chymopsin yielded collagen peptides with molecular weights from 900 to 7000 Da, while Caripazim processing yielded collagen peptides with lower molecular weights from 250 to 780 Da consisting of 2-8 amino acids, which could be easily absorbed and intensely incorporated in the formation of the joint tissue structures.

Development of Low-Molecular Weight Collagen Peptide Complex with Glycosaminoglycan Components.

Enzymatic hydrolysis of biopolymers of the cartilage tissue was studied for obtaining a complex of type II collagen peptides and glycosaminoglycan oligosaccharides. Hydrothermal hydrolysis in a high pressure homogenizer followed by enzymatic hydrolysis of the cartilage tissue biopolymers with proteolytic enzyme preparation Karipazim yielded a complex of collagen peptides and glycosaminoglycan oligosaccharides with molecular weights of 240-720 Da. Low molecular weight of the components increases their bioavailability. Entering into the cells (chondrocytes), low-molecular-weight peptides, disaccharides, and oligosaccharides as structural elements of the matrix can participate in the formation of fibrils of collagen and proteoglycans. Exogenous substances replenish deficient components of the matrix and/or their concentrations, affect the formation and strengthen the cartilage tissue. Thus, using cattle and porcine hyaline cartilages, we prepared a complex of biopolymers with lower molecular weights in comparison with previously developed nutraceuticals.

[Collagen fibril formation in vitro at temperatures close to physiological values].

Fibril formation of collagen from porcine skin was studied at temperatures of 28-39 degrees C. Collagen fibrils obtained in this temperature range have the different degree of order. An optimal temperature for the formation of collagen fibrils is found to be 36.5 degrees C; the structure of fibrils formed at this temperature is more homogeneous than that formed at 34.5 degrees C and 38.5 degrees C. As indicated by electron microscopy data, fibrils with a minimal diameter are formed at physiological values of pH, ionic strength, and temperature. The greater diameter of fibrils formed at 34.5 degrees C is due to a high level of hydration of collagen molecules. Fibril diameter is larger at 38.5 degrees C owing to the cooperative unfolding of the triple helix and a weakening of the binding of collagen molecules.

[Does collagen microunfolding stimulate the fibril formation?].

The data on the effect of temperature on the kinetics of collagen fibril formation at physiological pH values and ionic strength in the temperature range 26-39 degrees C have been analyzed. The temperature of 35 degrees C optimal for collagen fibril formation has been defined as the turning point for halfmaximal turbidity and collagen molecule microunfolding values, which corresponds to the temperature of the first transition on the heat absorption curve. The temperature range (32-35 degrees C) in which collagen microunfolding stimulates fibril formation has been determined.

[Structural and thermodynasmic aspects of the packing of collagen fibrils].

Studies devoted to the analysis of the mechanisms of packing of collagen fibrils and the effect of the macromolecular structure and the physicochemical parameters of medium on the packing are reviewed.

[Thermodynamic characteristics of collagen fibrils reconstructed in vitro at different temperatures and concentrations].

The results of a calorimetric study of type I collagen fibrillogenesis were analyzed. The dependence of the half-width of the temperature transition of a collagen solution on the concentration and temperature of collagen formation was studied. It was demonstrated that, by varying temperature and collagen concentration, one can regulate the density of packing and dimensions of cooperative fibril blocks. At temperatures below the physiological level (25 degrees C and 30 degrees C), and a relatively low concentration of collagen (0.3 mg/ml), fibrils with the lowest density of packing are formed. The degree of order does not change as the collagen concentration increases twofold but grows as the concentration increases fourfold. It was shown that, at the physiological temperature (35 degrees C), fibrils with a dense packing of molecules are formed at all collagen concentrations studied. The value of fibril formation enthalpy is minimal at a temperature of 35 degrees C, pH 7.2, an ionic strength of 0.17 M and a concentration of 1.2 mg/ml. Based on the results obtained, a conclusion was made that the packing density of fibrils formed at physiological temperature does not depend on collagen concentration over the concentration range of 0.3 - 1.2 mg/ml.

[Formation of collagen type I fibrils in vitro]. / Issledovanie obrazovaniia fibrill kollagena tipa I in vitro.

The assembly of collagen fibrils as a function of temperature and collagen concentration was studied. It was shown that temperature increases from 25 to 35 degrees C, the degree of ordering of collagen fibrils increases 1.5-fold at collagen concentration above 1 mg/ml and 2-fold at low collagen concentration. A maximum ordering of fibril structure occurs under conditions close to physiological (T approximately 35 degrees C and collagen concentration 1.2 mg/ml). As temperature is elevated from 30 to 35 degrees C, the packing of collagen molecules in fibrils becomes more ordered: the values of enthalpy and entropy of the transition of fibrils from the native to a disordered state decrease at all collagen concentrations used. At high collagen concentration, the dimensions of cooperative blocks in fibrils formed at 25 and 30 degrees C coincide with those of cooperative blocks of monomeric collagen in solution. Upon increasing the temperature to 35 degrees C, the dimensions of cooperative blocks increase.

[Self-assembly of collagen type I molecules without telopeptides]. / Izuchenie samosborki molekul kollagena tipa I s udalennymi telopeptidami.

The effect of temperature on the kinetics of formation of fibrils from rat tail collagen molecules devoid of telopeptides was studied. It was shown that the rats of fibril formation at 30 and 35 degrees C increases five- and eightfold, respectively, as compared with that at 25 degrees C. It was found that enthalpy of fibril denaturation at 30 degrees C is maximal for the collagen both with intact telopeptides and devoid of telopeptides. It was found that essential for the fibrilogenesis of type I collagen devoid of telopeptides are temperatures of 30 and 35 degrees C.

[Use of polarized thermomicroscopy for recording formation and degrading processes of collagen fibrils]. / Primenenie poliarizatsionnoi termomikroskopii dlia registratsii protsessov formirovaniia i degradatsii kollagenovykh fibrill.

Polarized thermomicroscopic method were used for registration of collagen fibril formation and thermal degradation processes. It was compared with differential scanning microcalorimetry and optical density measurement methods and recommended as a fast method for registration of collagen fibril formation and degradation processes.

[Collagen gels, chondroitin-4-sulfate. Proteolytic stability]. / Kollagenovye geli, khondroitin-4-sul'fat, ustoichivost' k proteolizu.

Differential scanning microcalorimetry and polarized thermomicroscopic methods were used for studying of collagen type I and chondroitin-4-sulfate complexes. It was shown that fast heating till 37 degrees C lead to collagen gel formation, which is stable for collagenase action.

[Results of the evaluation of a self-administered questionnaire in ophthalmology]. / Rezul'taty aprobatsii voprosnika dlia avtointerv'iuirovaniia po razdelu "oftal'mologiia".

The suggested questionnaire in ophthalmology consists of 24 questions of case history and complaints with consideration for age. It was tried with 101 patients. The study has shown that premedical interview helps single out subjects with normal eyes, who have some complaints and therefore should be consulted by an ophthalmologist, and patients with impaired refraction, who should be consulted by an optometrist of ophthalmoergonomist; these groups have made up 10.9, 41.5, and 47.6 percent of those interviewed.