[Effect of long-term microgravity on the vestibular function].

Comprehensive computerized oculomotor testing was used to investigate the vestibular function in 9 Russian members of ISS crews 3-9 on days 1 (2), 4 (5) and 8 (9) of return from long-term stay in microgravity (126 to 195 days). The vestibular function was assessed by the static otolith-cervical-ocular reflex, dynamic otolith-cervical-ocular reactions, vestibular reactivity, and spontaneous oculomotor activity. The postflight investigations revealed functional disorders in the peripheral (an increased vestibular reactivity, absent or damped otolith-cervical-ocular reflex), and central (spontaneous typical and atypical nystagmus, gaze nystagmus) vestibular analyzer. The pattern and extent of vestibular disorders after long-term exposure in microgravity were individual by character; however, some of the vestibular reactions, including disappearance or considerable damping of the static otolith-cervical-ocular reflex, exaggerated vestibular reactivity and spontaneous eye movements, displayed consistency.

[An experimental study on the effects of high pressure on adsorption properties of silochrome C-120]. / Eksperimental'noe izuchenie vliianiia povyshennogo davleniia na adsorbtsionnye svoistva silokhroma C-120.

Adsorption properties of silochrome in a helium atmosphere at 77 as were investigated. It was demonstrated that at a high pressure adsorption properties of silochrome changed and Henry coefficients decreased.

[Extracellular serine proteinase A of Streptomyces rutgersensis]. / Vnekletochnaia serinovaia proteinaza A Streptomyces rutgersensis.

Extracellular serine proteinase of Streptomyces rutgersensis (proteinase A) has been isolated by affinity chromatography on bacitracin-Sepharose in the presence of Na2EDTA. The proteolytic activity of the enzyme is completely suppressed by specific inhibitors of serine proteinases, phenylmethylsulfonylfluoride and diisopropylfluorophosphate, but is insensitive to Na2EDTA and sodium p-hydroxymercuribenzoate. The enzyme activity towards hemoglobin is maximal at pH 9-10, the maximal stability is observed within the pH range of 6-10. The molecular mass as determined by SDS-pore gradient electrophoresis is equal to 20000 +/- 2000. Proteinase A is similar to the proteinases A and B of Streptomyces griseus in terms of i) amino acid composition--Asp17Thr22Ser23Clu7Pro6. X Gly30Ala13Cys4Val18Met1Ile5Leu9Tyr10Phe6Trp1His2Arg7, ii) amino terminal sequence--Leu-Ser-Gly-Gly-Asp-Ala-Ile-Tyr-Ser-Asn-Ser-Ser-Xaa-Xaa-Ser-Leu-, iii) specificity of insulin B-chain hydrolysis, and iiii) ability to exhibit proteolytic activity in 8 M urea or 6 M guanidinium chloride. The enzyme lyzes the cells of Candida utilis. Besides proteinase A, S. rutgersensis produces at least two other proteolytic enzymes.

[Isolation and characterization of the lytic enzyme from Bacillus subtilis 797]. / Vydelenie i kharakteristika liticheskogo fermenta iz Bacillus subtilis 979.

The isolation procedure and some properties of the lytic enzyme produced by Bacillus subtilis 797 and capable of hydrolyzing the E. coli K-12 cells are described. Using hydrophobic chromatography on DNP-hexamethylene diamine Sepharose 4B and ion-exchange chromatography on DEAE-cellulose, a highly purified enzyme preparation with mol. weight of 28000, pI 8.2 has been obtained. The amino acid composition of the enzyme has been determined: Asp--37, Thr--17, Ser--34, Glu--15, Pro--14, Gly--17, Ala--36, Val--28, Met--4, Ile--11, Leu--17, Tyr--9, Phe--4, Lys--18, His--5, Arg--4. The enzyme is inhibited by a specific inhibitor of serine proteinases--benzylsulfonylfluoride, and is insensitive to EDTA and iodoacetic acid. The lytic enzyme has a proteolytic activity and splits the peptide substrate of bacterial serine proteinases--p-nitroanilide benzyloxycarbonyl-L-analyl-L-alanyl-L-leucine; the maxima for both activities lie within the pH range of 7.8-8.5. The lytic protease has the highest stability at pH 6-10. In some of its properties the enzyme is similar to serine proteinase from Bac. subtilis, i. e. subtilisins.

[Chromatography of carboxylic proteinases on sorbents containing the 2,4-dinitrophenyl group. Role of ionic interactions]. / Kromatografiia karboksil'nykh proteinaz na sorbentakh, soderzhashchikh 2,4-dinitrofenil'nuiu gruppy. Rol' ionnykh vzaimodeistvii.

The chromatography of porcine pepsin on biospecific sorbents (Sepharose-4B-epsilon-DNP-aminocapronylhydrazide and Sepharose-4B-N-DNP-N'-acetylhexamethylenediamine) was studied. The sorbents in question differ from the previously used hydrophobic sorbent Sepharose-4B-DNP-hexamethylenediamine by the lack of strongly basic groups in the site of the ligand binding to the polymeric matrix. No qualitative differences in the pepsin chromatography on the three sorbents were observed. Presumably the decrease of the pepsin binding to the sorbents, containing the dinitrophenyl group, at pH values above the isoelectric point may be due to the effects of the salt on the binding site in the enzyme molecule rather than to the screening of the positive charges of the sorbent by chlorine ions. A commercial preparation of pepsin was purified 2-fold on the sorbent Sepharose-4B-epsilon-DNP-animocapronylhydrazide. The synthesis of sorbents is described.

Chromatography of acid proteinases and chymotrypsin on a sorbent containing 2,4-dinitrophenyl residues.

A sorbent obtained by treatment of cyanogen bromide-activated Sepharose 4B with mono-N-DNP-hexamethylenediamine has been shown to be effective in the affinity chromatography of pepsin, pepsinogen and acid proteinase from Aspergillus awamori. It is considered that 2,4-dinitrophenyl residues of the sorbent interact specifically with the hydrophobic zone of the enzyme, which may belong to the substrate binding site. The chromatography of chymotrypsin on the same sorbent supports this assumption.