[Evaluation of preservation and the collagen structure state in the mummy tissues].

The content and state of collagen in skin, muscle and bone of 2500-year-old Altai mummies were studied. Collagen is the predominant protein in studied tissues of the mummies. High degree of the resistance of collagen to the effect of various proteases (collagenase, pronase, pepsin) and to alkline and acidic hydrolysis suggests on the considerable chemical modification of tissue collagen structures of the mummy.

[Characteristics of elastin from the wall of human large arteries during treatment with formaldehyde].

Biochemical studies of elastin from human large arteries wall were carried out using both native and treated with formaldehyde protein. No differences were observed in sensitivity of native and formaldehyde treated elastin to the effect of various proteases and to alkaline-alcohol hydrolysis. Fractions obtained after enzymatic and alkaline hydrolysis were similar in their composition.

[Photo-induced destruction of DOPA-melanin].

Studies of the effect of illumination at different wavelengths revealed a high stability of DOPA-melanin to the visible light. Contrariwise, UV-visible light of high intensity upon prolonged (many hours) illumination caused a significant bleaching of the diluted aqueous solution of the pigment. The absorption spectrum of DOPA-melanin in the UV- and IR-regions did not differ from the initial one; however, the illuminated pigment acquired an ability for fluorescence.

[A spectrofluorometric method of recording oxidation products of eumelanin destruction].

Dynamics of oxidative destruction of DOPA-melanin and melanin proteins was studied after treatment with 3% hydrogen peroxide within 60 min at 100 degrees. The pigments were estimated by absorption at 400 nm as well as by means of spectrofluorimetric patterns both in total preparation and in preparation obtained after fractionation on Tojapearl-55 and Tojapearl-40. Intensive fluorescence in the region 500-510 nm was detected within initial steps of oxidation while the absorption spectrum was unaltered.

[Characteristics of the modified effect of formaldehyde on various fractions of collagen].

Acid-soluble and insoluble fractions of collagen were dissimilarly modified by formaldehyde. The insoluble fraction became more stable to proteolysis by pronase, collagenase and pepsin.