PubMed Health⌕ Search

Biomedical subjects

E V Navolotskaia

Publications and source records attributed to E V Navolotskaia.

10 recordsLinked to original sources
PubMed2000

[Hormone-like activity of a synthetic decapeptide with the adrenocorticotropin-like sequence of human immunoglobulin G1].

The antiproliferative and immunosuppressive in vitro effects of immunocortin, a synthetic adrenocorticotropin-like (ACTH-like) decapeptide H-Val-Lys-Lys-Pro-Gly-Ser-Ser-Val-Lys-Val-OH, whose sequence corresponds to segment 11-20 of the variable part of the human IgG1 heavy chain, were studied. At concentrations of 10(-11)-10(-7) M, immunocortin was found to inhibit the growth of the human MT-4 T-lymphoblastoid cell line, to suppress the blast transformation of thymocytes, and to decrease the spontaneous mobility of peritoneal macrophages and their bactericidal action toward the virulent strain Salmonella typhimurium 415. By using a 125I-labeled "addressing" fragment of ACTH ¿[125I]ACTH-(13-24)¿, we showed that MT-4 cells express specific receptors for ACTH (Kd 97 pM). Immunocortin and human ACTH (but not the heavy chain of IgG1) competitively inhibited the binding of [125I]ACTH-(13-24) to these receptors with Ki1 of 0.38 and Ki2 of 0.34 nM, respectively. Specific receptors for ACTH (Kd 5.8 nM) on mouse thymocytes were detected and characterized. The unlabeled immunocortin was shown to complete with labeled ACTH-(13-24) for binding to these receptors (Ki = 1.8 nM) and this binding of immunocortin to receptors on thymocytes activates adenylate cyclase from these cells and increases the intracellular concentration of cAMP.

Adrenocorticotropic Hormone↗
PubMed2000

[Biologically active fragment of the differentiation factor from HL-60 cell line. Identification and properties].

Six-membered peptide fragment TGENHR (HLDF-6) was identified in the HL-60 cell culture of human promyelocyte leukemia treated with retinoic acid when studying the differentiation factor HLDF of this cell line. HLDF-6 retains the ability of the full-size factor to induce the differentiation and arrest the proliferation of the starting HL-60 cells. It was shown that the synthetic peptide HLDF-6 has no specific receptors on the surface of the HL-60 cells but can affect the binding of interleukin IL-1 beta, a cytokine involved in proliferation, to the cell surface. It was found on a model of transplantable NSO myeloma that HLDF-6 has an antitumor activity.

Animals↗
PubMed1999

[L-glutamic acid--a modulator of the physiological status of myeloid series blood cells].

The effects of L-glutamic acid on the differentiation of HL-60 and K-562 cell lines and on the expression level of mRNAs encoding IL-1 beta, IL-6, and TNF alpha were studied. It was shown that TNF alpha actively induces the differentiation of these cell lines, whereas L-glutamic acid enhances its effect. Our results indicated that L-glutamic acid modulates the physiological state of the myeloid cell line in blood, in particular, by affecting both the reception and expression of cytokines functionally important for these cells.

Bone Marrow Cells↗
PubMed1998

[Appearance of glutamate receptors on the surface of HL-60 cells upon differentiation].

A specific interaction of L-glutamic acid with promyelocytic leukemia HL-60 cells completely differentiated by all-E-retinoic acid (Kd = 0.5 microM) and by plasma membrane fraction from the same cells (Kd = 1 microM) was detected through radioligand analysis and characterized. Quisqualate, a nonlabeled structural analogue of glutamic acid, was found to inhibit competitively the specific binding of L-[3H]glutamic acid to the membranes (Ki = 0.24 microM). The stereospecificity of the binding was demonstrated. These data suggest that specific glutamate receptors appear on the surface of HL-60 cells during their differentiation.

Cell Differentiation↗
PubMedDate not supplied

[Stress-protective effect of the synthetic ACTH-like peptide leucocorticotropin].

We found that the tritium-labeled synthetic ACTH-like octapeptide leucocorticotropin corresponding to the 81-88 sequence of the precursor of human interleukin-1alpha ([3H]GKVLKKRR) is bound by the ACTH receptor of rat adrenal cortex with a high affinity and specificity (Kd 2.2 +/- 0.1 nM). This peptide was shown to exert no effect on the adenylate cyclase activity of the membranes of rat adrenal cortex in the concentration range from 1 to 1000 nM. Leucocorticotropin administration three times at doses of 10-20 microg/animal did not change the level of hydroxycorticosteroids (11-HOCS) in the rat adrenal glands in the absence of temperature action. At the same time, the peptide abolishes (at a dose of 20 microg/animal, three times) or significantly decreases (at a dose of 10 microg/animal, three times) the dramatic increase in the 11-HOCS content in the adrenal glands occurring in the case of cold or heat shock. Thus, leucocorticotropin normalizes the 11-HOCS level in the rat adrenal cortex during stress. The stress-protective effect of the peptide is mediated through the ACTH receptor.

Administration, Intranasal↗
PubMedDate not supplied

[Interaction of synthetic decapeptide SLTCLVKGFY with human T lymphocytes].

The synthetic peptide SLTCLVKGFY, corresponding to the 364-373 amino acid sequence of the human IgG heavy chain (Immunorphin), was found to compete with [125I] beta-endorphin for binding by high-affinity receptors on T lymphocytes isolated from the blood of healthy donors (Ki 0.6 nM). The fragments 3-10, 4-10, 5-10, and 6-10 of Immunorphin also inhibited the binding (Ki 2.2, 3.4, 8.0, and 15 nM, respectively). Specificity of these receptors was studied: they turned out to be insensitive to naloxone and, therefore, are not opioid. The Kd values of the specific binding of 125I-labeled Immunorphin and its 6-10 fragment to the receptor were found to be 7.4 and 36.3 nM, respectively.

Binding, Competitive↗
PubMedDate not supplied

[Effect of homologous peptides of differentiation factors HLDF and PEDF on preimplantation development of mice in vitro].

We studied the effect of synthetic peptides PEDF-6 and HLDF-6 on preimplantation development of mouse embryos in vitro. PEDF-6 peptide corresponds to fragment 351-356 and of pigment epithelium-derived differentiation factor (PEDF), while HLDF-6 peptide corresponds to fragment 84-89 of differentiation factor HLDF isolated from HL-60 cell line. Despite high homology, these peptides had different effects on the early development. PEDF-6 had no effect on the cleavage of 2-4-cell embryos but decelerated blastocyst formation from such embryos and disturbed their structure. In the presence of HLDF-6 the blastomeres divided more actively as compared to the control and a higher number of embryos developed to the blastocyst stage. The effects of both peptides were stage-specific: the affect the embryos at early cleavage stages and, apparently, determine their further development at that moment although do not directly affect formation of the blastocysts.

Animals↗
PubMedDate not supplied

[An ACTH-like peptide immunocortin: effect on the activity of cells from the rat adrenal cortex].

The effect of immunocortin, an ACTH-like decapeptide VKKPGSSVKV corresponding to the 11-20 sequence of the variable part of the human IgG1 heavy chain on the content of 11-hydroxycorticosteroids (CS) in rat adrenal glands and blood serum in vivo was studied. An intramuscular injection of immunocortin at a dose of 10 microg/kg was found in an hour to induce a twofold decrease in CS content in the adrenal glands and a 1.8-fold increase in the blood serum CS content. At the same time, an immunocortin dose of 100 microg/kg exerted practically no effect on the CS content and its dose of 1000 microg/kg increased the CS content both in adrenal glands and in blood serum by 1.6 and 2.2 times, respectively. Four hours after the injection of any of the three doses of immunocortin, the CS content in adrenal glands did not differ from the control value, and after 24 h the content decreased threefold. Immunocortin was shown to be bound by the ACTH receptors in the membranes of the rat adrenal cortex with a high affinity and specificity (inhibiting the specific binding of 125I-labeled ACTH-(11-24) peptide with Ki of 1.2 nM).

11-Hydroxycorticosteroids↗
PubMedDate not supplied

[Artificial proteins with a given spatial structure and biological activity].

Biologically active fragment 131-138 of human interferon alpha 2 carrying blast-transforming activity of the protein was attached to the N-terminus of the de novo protein albebetin with predetermined tertiary structure by means of genetic engineering. The chimeric protein was expressed in a wheat germ cell-free translation system and tested for compactness, stability and biological activity. According to the tests used albebetin with interferon fragment has a compact and relatively stable structure. It binds murine thymocyte receptor with high affinity and activates efficiently thymocyte blast transformation at a concentration of 10(-11) M.

Amino Acid Sequence↗