[Protein synthesis and content of free amino acids in rat organs in experimental peritonitis]. / Sintez belkov i soderzhanie svobodnykh aminokislot v organakh krys v dinamike éksperimental'nogo peritonita.

Experiments performed on rats shown that in peritonitis the mass of the animal's organs and C14-amino acid incorporation into tissue proteins is reduced. Free amino acid content in tissues and serum is increased. Decreased incorporation of C14-amino acid into hepatic proteins antecedes the increase of free amino acid content in this organ. In the kidneys, spleen and skeletal muscles diminished synthesis of proteins and increased protein catabolism occur simultaneously. It was shown that during the initial 24 hours of peritonitis the amino acid exchange between organs and systemic circulation are disturbed, however, the diminished synthesis of tissue proteins is not the result of free amino acid deficiency.

[Biosynthesis of proteins in various organs of albino rats in experimental peritonitis]. / Biosintez belkov v razlichnykh organakh belykh krys pri éksperimental'nom peritonite.

Protein biosynthesis and the state of polysomes were studied in rat liver and spleen tissues under conditions of acute purulent peritonitis of abdominal cavity. In the both tissues studied synthesis of proteins was markedly inhibited at the initial period of the peritonitis development within 6 hrs, these patterns were further increased within 12-48 hrs but they remained lower the control values. The structure-functional impairments of polysomes were most distinct within 24-48 hrs after the disease beginning.

[RNA biosynthesis in various organs of the rat in experimental peritonitis]. / Issledovanie biosinteza RNK v razlichnykh organakh krys pri éksperimental'nom peritonite.

Synthesis of various RNA species was studied in liver, spleen, and kidney tissues of one year old Wistar rat males within 6, 12, 24 and 48 hrs after peritonitis development. RNA biosynthesis was found to be unaltered in kidney; in liver tissue it was distinctly decreased beginning from 24 hrs and lowered down to 40% of the control value within 2 days. In spleen an increase in synthesis of pro-mRNA (90%) and mRNA was observed at early steps of peritonitis, with the subsequent decrease of these patterns within 24-48 hrs as compared with the previous periods of the disease as well as with controls. The most pronounced inhibition of RNA synthesis (pro-mRNA, mRNA) coincided in time with death of the animals.

[Nuclear RNP containing pre-mRNA. 16. Cross-linked informofers]. / Iadernye RNP, Soderszhashcie pre-mRNK. XVI. "Zashitye" informofery.

The proteins of 30S RNP particles containing pre-mRNA (hnRNA) were cross-linked with bifunctional reagents (dimethylsuberimidate and dimethyl-3,3'dithiobispropionimi-date). Further treatment with 1 or 2 M NaCl dissociates all RNA from protein. However, a significant part of protein particles--informofers, being cross-linked survived high salt treatment. Their sedimentation coefficients were close to those of original particles. No RNA could be detected in the informofers even after labeling the cells with a precursor for a long period of time. Sodium dodecylsulfate or urea dissociated cross-linked informofers into oligomeric polypeptides. They could be dissociated by beta-mercaptoethanol treatment if a reversible cross-linking reagent has been used. The resulting polypeptides were represented by informatin. RNP particles (30S RNP or polyparticles) were reconstituted upon mixing or cross-linked informofers with pre-mRNA and removal of 2 M NaCl. The reconstituted particles were indistinguishable from the original ones by several tests.

Cross-linked informofers.

The proteins of 30S RNP particles containing pre-mRNA (hnRNA) were cross-linked with bifunctional reagents (dimethyl-suberimidate and dimethyl-3,3'-dithiobispropionimidate). Further treatment with 1 or 2 M NaCl dissociates all RNA from protein. However, a significant part of protein particles--informofers being cross-linked survived high salt treatment. Their sedimentation coefficients were close to those of original particles. No RNA could be detected in the informofers even after labeling the cells with a precursor for a long period of time. Sodium dodecylsulfate or urea dissociated cross-linked informofers into oligomeric polypeptides. They could be dissociated by beta-mercaptoethanol treatment if a reversible cross-linked reagent had been used. The resulting polypeptides were represented by informatin. RNP particles (30S RNP or poly-particles) were reconstituted upon mixing of cross-linked informofers with pre-mRNA and removal of 2 M NaCl.

[Nuclear ribonucleoproteins containing pro-mRNA. XIV. Structural study using ethidium and fluorescamine]. / Iadernye ribonukleoproteidy, soderzhashchie pro-mRNK. XIV. Issledovanie struktury s ispol'zovaniem étidiia i fluoreskamina.

Nuclear 30S RNP particles were studied by means of fluorescence techniques. It's shown that fluorescamin interacts with NH2-groups of protein molecule. As a result, covalent fluorescent label is formed. Quantum yield (rho), fluorescence spectra, lifetime of excited state (tau) and polarization of fluorescamin complexes with 30S particles were studied. Excitation spectra have their maximum at 395 nm, and fluorescence spectrum at 480 nm. These figures correspond to spectra of fluorescamin complexes with NH2-groups of lysine. Mean quantum yield (rho = 0.27) and lifetime of excited state of fluorescence (tau = 7.8 nsec) were measured. It's shown that fluorescamin forms two types of fluorescent complexes in 30S particles. These complexes differ only by their rho(rho1 = 0.11, rho2 = 0.30) and rho(rho1 = 3.6 nsec, rho2 = 10.0 nsec) by 2.7 times. Migration radius between fluorescamin bound to protein and ethydium bromide adsorbed on double-stranded regions of pre-mRNA in RNP-particles was measured. It's equal to 32 A. Adsorbtion isotherms of ethydium bromide were measured by fluorescence in 0.1 and 0.4 M NaCl. Data obtained showed that 6% of pre-mRNA in 30S particles bound the dye as a strong complex, i. e. this part of pre-mRNA is double-stranded. RNase treatment of RNP had no effect on this value. But the increase of NaCl concentration up to 0.4 M caused the dissociation of protein subunits to some extent followed by appearance of up to 40% free NH2-groups interacting with fluorescamin. Measuring of energy migration from fluorescamin to ethydium bromide showed that double-stranded pre-mRNA regions strictly bound to protein sticked out from RNP particle at a distance of about 27 A. The increase of NaCl concentration up to 0.4 M leads to disruption of this strict bond of double-stranded regions with protein. As a result, these regions of pre-mRNA become labile and move away from the RNP particle at more than 30 A. According to theoretical calculations, there is about 1--2 pre-mRNA hairpins (18--9 base pairs respectively) per one 30S particle.

[Nuclear RNP, containing pre-mRNA. XIV. Nature of particles, containing 5'- and 3'-end structures]. / Iadernye RNP, soderzhashchie pro-mRNK. XIV. Priroda chastits, soderzhashchikh 5'-i 3'-kontsevye struktury.

Some characteristic peculiarities of the 5'-end and 3'-end structures of pre-mRNA isolated from nuclear RNP particles have been investigated: presence of triphosphorylated nucleotides on the 5'-ends, as a characteristic of the primary product of transcription; presence of modified 5'-ends -- blocked and methylated structures -- caps; presence of poly(A) blocks attached to the 3'-end of pre-mRNA during post-transcriptional transformation of the latter. It was shown that pre-mRNA isolated from nuclear RNP particles contained triphosphorylated nucleotides as well as a "cap" structure at the 5'-ends. On the 3'-ends of pre-mRNA from nuclear RNP particles isolated in the presence of a RNAse inhibitor, the presence of poly(A) blocks have been shown. These poly(A) structures are separated very easily from pre-mRNA during mild RNAase digestion. This is the reason why they are not detected in 30S monoparticles, containing pre-mRNA fragments connected with one informofer. Almost all poly(A) complexes in this condition are combined with proteins and have the sedimentation coefficient of about 14S. It was concluded that formation of nuclear pre-mRNA containing RNP-particles take place just after the onset of RNA synthesis. All processing steps occur with pre-mRNA packed in nuclear RNP particles.