[7-Glycine]deamino-1-carba-vasopressin: Synthesis and pharmacological properties

1981 ◽  
Vol 46 (1) ◽  
pp. 278-285 ◽  
Author(s):  
František Brtník ◽  
Tomislav Barth ◽  
Karel Jošt
Keyword(s):  
Substantial Decrease ◽  
Pharmacological Properties ◽  
Amino Terminal ◽  
Glycine Derivative ◽  
Carboxy Terminal ◽  
Cyclic Part ◽  
Vasopressin Synthesis

[8-Arginine]deamino-1-carba-vasopressin and its 7-glycine derivative were prepared by condensation of the amino-terminal, cyclic part of the molecule with carboxy-terminal tripeptide amides. Replacement of proline by glycine in the position 7 results in a substantial decrease in the vasopressin-like activities, the oxytocin-like activities remaining unchanged.

[9-Aminoacetone]oxytocin and [8-p-aminobenzamide, 9-des-glycinamide]oxytocin: Chemical synthesis and properties

1982 ◽  
Vol 47 (1) ◽  
pp. 338-348 ◽  
Author(s):  
Jan Hlaváček ◽  
Ivo Frič ◽  
Tomislav Barth ◽  
Karel Jošt
Keyword(s):  
Chemical Synthesis ◽  
Structural Changes ◽  
Biological Activities ◽  
Cd Spectra ◽  
Terminal Part ◽  
Amino Terminal ◽  
Carboxy Terminal ◽  
Cyclic Part

[9-Aminoacetone]oxytocin and [8-p-aminobenzamide, 9-des-glycinamide]oxytocin were prepared by condensation of amino-terminal linear hexapeptide with peptides simulating the carboxy-terminal tripeptide chain of oxytocin, according to the 6 + 3 scheme. Both the analogues had significantly lower biological activities than oxytocin. CD spectra of the analogues were compared with those of oxytocin and [9-des-glycine]oxytocin in order to study the effect of structural changes in the carboxy-terminal part of the analogues on the conformation of their cyclic part.

Interaction Between Mutations in the suppressor of Hairy wing and modifier of mdg4 Genes of Drosophila melunogaster Affecting the Phenotype of gypsy-Induced Mutations

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Pavel Georgiev ◽  
Marina Kozycina
Keyword(s):  
Mutagenic Effect ◽  
Induced Mutations ◽  
Binding Region ◽  
Direct Inhibition ◽  
Amino Terminal ◽  
Acidic Domain ◽  
Complete Inactivation ◽  
Insulation Effect ◽  
Gypsy Retrotransposon ◽  
Carboxy Terminal

Abstract The suppressor of Hairy-wing [su(Hw)] protein mediates the mutagenic effect of the gypsy retrotransposon by repressing the function of transcriptional enhancers located distally from the promoter with respect to the position of the su(Hw)-binding region. Mutations in a second gene, modifier of mdg4, also affect the gypsy-induced phenotype. Two major effects of the mod(mdg4)lul mutation can be distinguished: the interference with insulation by the su(Hw)-binding region and direct inhibition of gene expression that is not dependent on the su(Hw)-binding region position. The mod(mdg4)lul mutation partially suppresses ct6, scD1 and Hw1 mutations, possibly by interfering with the insulation effect of the su(Hw)-binding region. An example of the second effect of mod(mdg4)lul is a complete inactivation of yellow expression in combination with the y  2 allele. Phenotypic analyses of flies with combinations of mod(mdg4)lul and different su(Hw) mutations, or with constructions carrying deletions of the acidic domains of the su(Hw) protein, suggest that the carboxy-terminal acidic domain is important for direct inhibition of yellow transcription in bristles, while the amino-terminal acidic domain is more essential for insulation.

scholarly journals p190 RhoGAP, the major RasGAP-associated protein, binds GTP directly.

1994 ◽  
Vol 14 (11) ◽  
pp. 7173-7181 ◽  
Author(s):  
R Foster ◽  
K Q Hu ◽  
D A Shaywitz ◽  
J Settleman
Keyword(s):  
Structural Features ◽  
Cellular Protein ◽  
Small Gtpases ◽  
Sequence Motifs ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Gtp Binding ◽  
Guanine Nucleotide Binding ◽  
Complex Forms ◽  
Carboxy Terminal

In mitogenically stimulated cells, a specific complex forms between the Ras GTPase-activating protein (RasGAP) and the cellular protein p190. We have previously reported that p190 contains a carboxy-terminal domain that functions as a GAP for the Rho family GTPases. Thus, the RasGAP-p190 complex may serve to couple Ras- and Rho-mediated signalling pathways. In addition to its RhoGAP domain, p190 contains an amino-terminal domain that contains sequence motifs found in all known GTPases. Here, we report that p190 binds GTP and GDP through this conserved domain and that the structural requirements for binding are similar to those seen with other GTPases. While the purified protein is unable to hydrolyze GTP, we detect an activity in cell lysates that can promote GTP hydrolysis by p190. A mutated form of p190 that fails to bind nucleotide retains its RasGAP binding and RhoGAP activities, indicating that GTP binding by p190 is not required for these functions. The sequence of p190 in the GTP-binding domain, which shares structural features with both the Ras-like small GTPases and the larger G proteins, suggests that this protein defines a novel class of guanine nucleotide-binding proteins.

N-Terminal amino acid sequence of rat tonin: homology with serine proteases

1978 ◽  
Vol 56 (9) ◽  
pp. 920-925 ◽  
Author(s):  
N. G. Seidah ◽  
R. Routhier ◽  
M. Caron ◽  
M. Chrétien ◽  
S. Demassieux ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Terminal Sequence ◽  
Renin Substrate ◽  
Amino Terminal ◽  
Single Polypeptide Chain ◽  
Serine Protease Family ◽  
Terminal Amino ◽  
Single Polypeptide ◽  
Carboxy Terminal ◽  
Amino Terminal Sequence

In this paper, we present the amino-terminal sequence of rat tonin, an endopeptidase responsible for the conversion of angiotensinogen, the tetradecapeptide renin substrate, or angiotensin I to angiotensin II. It is shown that isoleucine and proline occupy the amino- and carboxy-terminal residues respectively. The N-terminal sequence analysis permitted the identification of 34 out of the first 40 residue s of the single polypeptide chain composed of 272 amino acids. The se results showed an extensive homology with the sequence of many serine proteases of the trypsin–chymotrypsin family. This information, coupled with the slow inhibition of tonin by diisopropylfluorophosphate, classified this enzyme as a selective endopeptidase of the active serine protease family.

scholarly journals The Catenin p120ctnInteracts with Kaiso, a Novel BTB/POZ Domain Zinc Finger Transcription Factor

1999 ◽  
Vol 19 (5) ◽  
pp. 3614-3623 ◽  
Author(s):  
Juliet M. Daniel ◽  
Albert B. Reynolds
Keyword(s):  
Transcription Factor ◽  
Monoclonal Antibodies ◽  
Cell Adhesion ◽  
Mammalian Cells ◽  
Yeast Two Hybrid ◽  
Amino Terminal ◽  
Juxtamembrane Region ◽  
Carboxy Terminal ◽  
Two Hybrid ◽  
E Cadherin

ABSTRACT p120 ctn is an Armadillo repeat domain protein with structural similarity to the cell adhesion cofactors β-catenin and plakoglobin. All three proteins interact directly with the cytoplasmic domain of the transmembrane cell adhesion molecule E-cadherin; β-catenin and plakoglobin bind a carboxy-terminal region in a mutually exclusive manner, while p120 binds the juxtamembrane region. Unlike β-catenin and plakoglobin, p120 does not interact with α-catenin, the tumor suppressor adenomatous polyposis coli (APC), or the transcription factor Lef-1, suggesting that it has unique binding partners and plays a distinct role in the cadherin-catenin complex. Using p120 as bait, we conducted a yeast two-hybrid screen and identified a novel transcription factor which we named Kaiso. Kaiso’s deduced amino acid sequence revealed an amino-terminal BTB/POZ protein-protein interaction domain and three carboxy-terminal zinc fingers of the C2H2 DNA-binding type. Kaiso thus belongs to a rapidly growing family of POZ-ZF transcription factors that include the Drosophila developmental regulators Tramtrak and Bric à brac, and the human oncoproteins BCL-6 and PLZF, which are causally linked to non-Hodgkins’ lymphoma and acute promyelocytic leukemia, respectively. Monoclonal antibodies to Kaiso were generated and used to immunolocalize the protein and confirm the specificity of the p120-Kaiso interaction in mammalian cells. Kaiso specifically coprecipitated with a variety of p120-specific monoclonal antibodies but not with antibodies to α- or β-catenin, E-cadherin, or APC. Like other POZ-ZF proteins, Kaiso localized to the nucleus and was associated with specific nuclear dots. Yeast two-hybrid interaction assays mapped the binding domains to Arm repeats 1 to 7 of p120 and the carboxy-terminal 200 amino acids of Kaiso. In addition, Kaiso homodimerized via its POZ domain but it did not heterodimerize with BCL-6, which heterodimerizes with PLZF. The involvement of POZ-ZF proteins in development and cancer makes Kaiso an interesting candidate for a downstream effector of cadherin and/or p120 signaling.

scholarly journals Effects of point mutations in the cytidine deaminase domains of APOBEC3B on replication and hypermutation of hepatitis B virus in vitro

2007 ◽  
Vol 88 (12) ◽  
pp. 3270-3274 ◽  
Author(s):  
Marianne Bonvin ◽  
Jobst Greeve
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Point Mutations ◽  
Alternative Mechanism ◽  
Amino Terminal ◽  
Hbv Replication ◽  
B Virus ◽  
Carboxy Terminal ◽  
Deaminase Domain

APOBEC3 cytidine deaminases hypermutate hepatitis B virus (HBV) and inhibit its replication in vitro. Whether this inhibition is due to the generation of hypermutations or to an alternative mechanism is controversial. A series of APOBEC3B (A3B) point mutants was analysed in vitro for hypermutational activity on HBV DNA and for inhibitory effects on HBV replication. Point mutations inactivating the carboxy-terminal deaminase domain abolished the hypermutational activity and reduced the inhibitory activity on HBV replication to approximately 40 %. In contrast, the point mutation H66R, inactivating the amino-terminal deaminase domain, did not affect hypermutations, but reduced the inhibition activity to 63 %, whilst the mutant C97S had no effect in either assay. Thus, only the carboxy-terminal deaminase domain of A3B catalyses cytidine deaminations leading to HBV hypermutations, but induction of hypermutations is not sufficient for full inhibition of HBV replication, for which both domains of A3B must be intact.

Cell transformation by avian defective leukaemia viruses

1980 ◽  
Vol 210 (1180) ◽  
pp. 397-409 ◽  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Cell Transformation ◽  
Nucleic Acid Hybridization ◽  
Phenotypic Analysis ◽  
Amino Terminal ◽  
Cell Specificity ◽  
Core Proteins ◽  
Carboxy Terminal

A comparative study of seven independently isolated defective leukaemia viruses has been carried out. Phenotypic analysis of the chicken bone marrow cells transformed in vitro allowed the separation of these seven viruses into three groups based on the differentiation phenotype of the transformed cell. Nucleic acid hybridization studies revealed that these seven viruses had acquired cellular sequences. Interestingly, these studies also showed that the viruses within the same biological grouping had acquired related sequences. This indicates that viruses that have acquired the same or similar cellular sequences have very similar oncogenic capabilities. Analysis of proteins expressed in cells transformed by these viruses demonstrated that the cellular sequences were usually inserted within the gene for the viral core proteins, gag . Therefore the cellular sequences are expressed as a gag -related fusion protein which has an amino-terminal region derived from the gag gene and a carboxy-terminal half derived from the cellular sequences. Two exceptions to this are discussed. The general conclusion from these studies is that defective leukaemia viruses transform cells by virtue of acquired host cellular sequences. The ability of these viruses to transform cells and the target cell specificity of the transformation depends on these cellular sequences.

Structural differences between repressed and derepressed forms of p60c-src

1989 ◽  
Vol 9 (6) ◽  
pp. 2648-2656
Author(s):  
A MacAuley ◽  
J A Cooper
Keyword(s):  
Kinase Activity ◽  
Kinase Domain ◽  
Terminal Region ◽  
Phosphorylation Sites ◽  
Carboxy Terminus ◽  
Kinase Activation ◽  
Amino Terminal ◽  
Structural Differences ◽  
Carboxy Terminal ◽  
Pronase E

The kinase activity of p60c-src is derepressed by removal of phosphate from Tyr-527, mutation of this residue to Phe, or binding of a carboxy-terminal antibody. We have compared the structures of repressed and active p60c-src, using proteases. All forms of p60c-src are susceptible to proteolysis at the boundary between the amino-terminal region and the kinase domain, but there are several sites elsewhere that are more sensitive to trypsin digestion in repressed than in derepressed forms of p60c-src. The carboxy-terminal tail (containing Tyr-527) is more sensitive to digestion by pronase E and thermolysin when Tyr-527 is not phosphorylated. The kinase domain fragment released with trypsin has kinase activity. Relative to intact p60c-src, the kinase domain fragment shows altered substrate specificity, diminished regulation by the phosphorylated carboxy terminus, and novel phosphorylation sites. The results identify parts of p60c-src that change conformation upon kinase activation and suggest functions for the amino-terminal region.

Parathyroid hormone metabolism and its potential as a uremic toxin

1980 ◽  
Vol 239 (1) ◽  
pp. F1-F12 ◽  
Author(s):  
E. Slatopolsky ◽  
K. Martin ◽  
K. Hruska
Keyword(s):  
Renal Failure ◽  
Parathyroid Hormone ◽  
Chronic Renal Failure ◽  
Biological Effects ◽  
Uremic Toxin ◽  
Terminal Portion ◽  
Single Chain ◽  
Biochemical Alterations ◽  
Amino Terminal ◽  
Carboxy Terminal

Secondary hyperparathyroidism is a universal complication of chronic renal failure. It has been proposed that the markedly elevated levels of immunoreactive parathyroid hormone (i-PTH) in uremia may represent a “uremic toxin” responsible for many of the abnormalities of the uremic state. Plasma i-PTH consists of a mixture of intact hormone, a single-chain polypeptide of 84 amino acids, and smaller molecular weight hormonal fragments from both the carboxy- and amino-terminal portion of the PTH molecule. The hormonal fragments arise from metabolism of intact PTH by peripheral organs as well as from secretion of fragments from the parathyroid glands. The structural requirements for the known biological actions of PTH reside in the amino-terminal portion of the PTH molecule. Carboxy-terminal fragments, biologically inactive at least in terms of adenylate cyclase activation, hypercalcemia, or phosphaturia, depend on the kidney for their removal from plasma, and thus accumulate in the circulation in chronic renal failure. It is unknown at the present time if other biological effects of these carboxy-terminal fragments may contribute to some of the biochemical alterations observed in uremia. The most significant consequence of increased PTH levels in uremia is the development of bone disease characterized by osteitis fibrosa. In addition, it would appear that PTH plays an important role in some of the abnormal electroencephalographic patterns observed in uremia. This may be due to a potential role of PTH in increasing calcium content of brain. Parathyroid hormone also has been implicated as a pathogenetic factor in many other alterations present in uremia, i.e., peripheral neuropathy, carbohydrate intolerance, hyperlipidemia, and other alterations. Unfortunately, outstanding clinical research is lacking in this field and conclusive experimental data are practically nonexistent. Further studies are necessary if one is to accept the concept of PTH being a significant “uremic toxin.”

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