TSAO-T Analogues Bearing Amino Acids at Position N-3 of Thymine: Synthesis and Anti-Human Immunodeficiency Virus Activity

2000 ◽  
Vol 11 (1) ◽  
pp. 61-69 ◽  
Author(s):  
C Chamorro ◽  
E De Clercq ◽  
J Balzarini ◽  
M-J Camarasa ◽  
A San-Félix
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Inhibitory Effect ◽  
Acid Moiety ◽  
Hiv Replication ◽  
Virus Activity ◽  
Immunodeficiency Virus ◽  
Amino Acid Moiety ◽  
Anti Hiv ◽  
Hiv 1

Novel analogues of the anti-HIV-1 lead compound [1-[2‘,5’-bis- O-( tert-butyldimethylsilyl)-β-D-ribofuranosyl]thymine]-3‘-spiro-5’-(4“-amino-1”,2“-oxathiole-2‘,2’-dioxide) (TSAO-T) bearing different amino acids at position N-3 of thymine were prepared and evaluated as inhibitors of HIV replication. The synthesis of the target compounds was accomplished by coupling of the appropriate TSAO intermediate with a conveniently protected (L) amino acid in the presence of BOP and triethylamine, followed by depro-tection of the amino acid moiety. Several TSAO derivatives, bearing at N-3 position of the thymine base an L-amino acid retaining the free carboxylic acid, acquired activity against HIV-2, in addition to their inhibitory effect on HIV-1.

scholarly journals Phosphoramidates as Potent Prodrugs of anti-HIV Nucleotides: Studies in the Amino Region

1996 ◽  
Vol 7 (1) ◽  
pp. 31-36 ◽  
Author(s):  
C. McGuigan ◽  
D. Cahard ◽  
A. Salgado ◽  
E. De Clercq ◽  
J. Balzarini
Keyword(s):  
Amino Acid ◽  
Vital Role ◽  
Nucleoside Analogues ◽  
Acid Moiety ◽  
Hiv Replication ◽  
Amino Acid Moiety ◽  
Free Nucleotides ◽  
Derivatives Of ◽  
Anti Hiv

Novel phosphoramidate derivatives of the anti-HIV nucleoside analogues AZT and d4T have been prepared by phosphorochloridate chemistry. These materials are designed to act as labile membrane-soluble prodrugs of the bio-active free nucleotides. All compounds were fully characterised by a range of methods and were subjected to evaluation in vitro of their anti-HIV efficacy. A notable feature of the current study was that any attempt to replace the amino acid moiety of the phosphoramidate with a simple amine lead to a marked, virtually total loss of activity. Such simple phenyl alkylamino phosphate derivatives of either d4T or AZT inhibit HIV replication at cytotoxic concentrations and have no detectable antiviral selectivity. This clearly highlights the vital role played by the amino acid in the antiviral efficacy of the blocked phosphoramidates.

scholarly journals Mutational Analysis of the Hydrophobic Tail of the Human Immunodeficiency Virus Type 1 p6Gag Protein Produces a Mutant That Fails To Package Its Envelope Protein

1999 ◽  
Vol 73 (1) ◽  
pp. 19-28 ◽  
Author(s):  
David E. Ott ◽  
Elena N. Chertova ◽  
Laura K. Busch ◽  
Lori V. Coren ◽  
Tracy D. Gagliardi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Wild Type ◽  
Immunodeficiency Virus ◽  
Hydrophobic Tail ◽  
Carboxyl Terminal ◽  
Hiv 1

ABSTRACT The p6Gag protein of human immunodeficiency virus type 1 (HIV-1) is produced as the carboxyl-terminal sequence within the Gag polyprotein. The amino acid composition of this protein is high in hydrophilic and polar residues except for a patch of relatively hydrophobic amino acids found in the carboxyl-terminal 16 amino acids. Internal cleavage of p6Gag between Y36 and P37, apparently by the HIV-1 protease, removes this hydrophobic tail region from approximately 30% of the mature p6Gag proteins in HIV-1MN. To investigate the importance of this cleavage and the hydrophobic nature of this portion of p6Gag, site-directed mutations were made at the minor protease cleavage site and within the hydrophobic tail. The results showed that all of the single-amino-acid-replacement mutants exhibited either reduced or undetectable cleavage at the site yet almost all were nearly as infectious as wild-type virus, demonstrating that processing at this site is not important for viral replication. However, one exception, Y36F, was 300-fold as infectious the wild type. In contrast to the single-substitution mutants, a virus with two substitutions in this region of p6Gag, Y36S-L41P, could not infect susceptible cells. Protein analysis showed that while the processing of the Gag precursor was normal, the double mutant did not incorporate Env into virus particles. This mutant could be complemented with surface glycoproteins from vesicular stomatitis virus and murine leukemia virus, showing that the inability to incorporate Env was the lethal defect for the Y36S-L41P virus. However, this mutant was not rescued by an HIV-1 Env with a truncated gp41TM cytoplasmic domain, showing that it is phenotypically different from the previously described MA mutants that do not incorporate their full-length Env proteins. Cotransfection experiments with Y36S-L41P and wild-type proviral DNAs revealed that the mutant Gag dominantly blocked the incorporation of Env by wild-type Gag. These results show that the Y36S-L41P p6Gag mutation dramatically blocks the incorporation of HIV-1 Env, presumably acting late in assembly and early during budding.

[1.4]Diazepino[6.5-c]chinoline mit L-Aminosäurebaustein — Darstellung und Reaktionen / [1.4]Diazepino[6.5-c]quinolines with L-Amino Acid Moiety — Preparation and Reactions

1987 ◽  
Vol 42 (9) ◽  
pp. 1167-1173 ◽  
Author(s):  
Sabine Bohnert ◽  
Wolf-H. Gündel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Model Compound ◽  
Acid Moiety ◽  
Quaternary Salts ◽  
Amino Acid Moiety

Quaternary salts of the amides of N-(3-quinolinecarbonyl)-N-alkyl-amino acids (6) cyclise under the influence of base to the title compounds (7). This intramolecular addition is a reaction with high diastereoselectivity, dependent on the amino acid part. 7 disproportionates to 8 and 9. 7 behaves as lipophilic NAD model compound in the reaction with 2-propanol under ZnCl2 catalysis.

scholarly journals Human Immunodeficiency Virus Type 1 Env Sequences from Calcutta in Eastern India: Identification of Features That Distinguish Subtype C Sequences in India from Other Subtype C Sequences

2001 ◽  
Vol 75 (21) ◽  
pp. 10479-10487 ◽  
Author(s):  
Raj Shankarappa ◽  
Ramdas Chatterjee ◽  
Gerald H. Learn ◽  
Dhruba Neogi ◽  
Ming Ding ◽  
...  
Keyword(s):  
Amino Acids ◽  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Heterosexual Transmission ◽  
Subtype C ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT India is experiencing a rapid spread of human immunodeficiency virus type 1 (HIV-1), primarily through heterosexual transmission of subtype C viruses. To delineate the molecular features of HIV-1 circulating in India, we sequenced the V3-V4 region of viralenv from 21 individuals attending an HIV clinic in Calcutta, the most populous city in the eastern part of the country, and analyzed these and the other Indian sequences in the HIV database. Twenty individuals were infected with viruses having a subtype Cenv, and one had viruses with a subtype Aenv. Analyses of 192 subtype C sequences that included one sequence for each subject from this study and from the HIV database revealed that almost all sequences from India, along with a small number from other countries, form a phylogenetically distinct lineage within subtype C, which we designate CIN. Overall, CIN lineage sequences were more closely related to each other (level of diversity, 10.2%) than to subtype C sequences from Botswana, Burundi, South Africa, Tanzania, and Zimbabwe (range, 15.3 to 20.7%). Of the three positions identified as signature amino acid substitution sites for CIN sequences (K340E, K350A, and G429E), 56% of the CIN sequences contained all three amino acids while 87% of the sequences contained at least two of these substitutions. Among the non-CINsequences, all three amino acids were present in 2%, while 22% contained two or more of these amino acids. These results suggest that much of the current Indian epidemic is descended from a single introduction into the country. Identification of conserved signature amino acid positions could assist epidemiologic tracking and has implications for the development of a vaccine against subtype C HIV-1 in India.

scholarly journals A Second-Site Mutation That Restores Replication of a Tat-Defective Human Immunodeficiency Virus

1999 ◽  
Vol 73 (4) ◽  
pp. 2781-2789 ◽  
Author(s):  
Koen Verhoef ◽  
Ben Berkhout
Keyword(s):  
Amino Acids ◽  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Virus Replication ◽  
Suppressor Mutation ◽  
Large Set ◽  
Wild Type ◽  
Suppressor Mutations ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We previously constructed a large set of mutants of the human immunodeficiency virus type 1 (HIV-1) regulatory protein Tat with conservative amino acid substitutions in the activation domain. These Tat variants were analyzed in the context of the infectious virus, and several mutants were found to be defective for replication. In an attempt to obtain second-site suppressor mutations that could provide information on the Tat protein structure, some of the replication-impaired viruses were used as a parent for the isolation of revertant viruses with improved replication capacity. Sequence analysis of revertant viruses frequently revealed changes within thetat gene, most often first-site reversions either to the wild-type amino acid or to related amino acids that restore, at least partially, the Tat function and virus replication. Of 30 revertant cultures, we identified only one second-site suppressor mutation. The inactive Y26A mutant yielded the second-site suppressor mutation Y47N that partially restored trans-activation activity and virus replication. Surprisingly, when the suppressor mutation was introduced in the wild-type Tat background, it also improved thetrans-activation function of this protein about twofold. We conclude that the gain of function measured for the Y47N change is not specific for the Y26A mutant, arguing against a direct interaction of Tat amino acids 26 and 47 in the three-dimensional fold of this protein. Other revertant viruses did not contain any additional Tat changes, and some viruses revealed putative second-site Tat mutations that did not significantly improve Tat function and virus replication. We reason that these mutations were introduced by chance through founder effects or by linkage to suppressor mutations elsewhere in the virus genome. In conclusion, the forced evolution of mutant HIV-1 genomes, which is an efficient approach for the analysis of RNA regulatory motifs, seems less suited for the analysis of the structure of this small transcription factor, although protein variants with interesting properties can be generated.

scholarly journals Anti-Human Immunodeficiency Virus Activity of YK-FH312 (a Betulinic Acid Derivative), a Novel Compound Blocking Viral Maturation

2001 ◽  
Vol 45 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
Taisei Kanamoto ◽  
Yoshiki Kashiwada ◽  
Kenji Kanbara ◽  
Kazuyo Gotoh ◽  
Manabu Yoshimori ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Betulinic Acid ◽  
Electron Microscopic Observation ◽  
Syncytium Formation ◽  
Inhibition Assay ◽  
Hiv Replication ◽  
Electron Microscopic ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT Betulinic acid, a triterpenoid isolated from the methyl alcohol extract of the leaves of Syzigium claviflorum, was found to have a potent inhibitory activity against human immunodeficiency virus type 1 (HIV-1). Betulinic acid derivatives were synthesized to enhance the anti-HIV activity. Among the derivatives, 3-O-(3′,3′-dimethylsuccinyl) betulinic acid, designated YK-FH312, showed the highest activity against HIV-induced cytopathic effects in HIV-1-infected MT-4 cells. To determine the step(s) of HIV replication affected by YK-FH312, a syncytium formation inhibition assay in MOLT-4/HIV-1IIIB and MOLT-4 coculture, a multinuclear-activation-of-galactosidase-indicator (MAGI) assay in MAGI-CCR5 cells, electron microscopic observation, and a time-of-addition assay were performed. In the syncytium formation inhibition assay or in the MAGI assay for de novo infection, the compound did not show inhibitory effects against HIV replication. Conversely, no virions were detected in HIV-1-infected cell cultures treated with YK-FH312 either by electron microscopic observation or by viral yield in the supernatant. In accordance with a p24 enzyme-linked immunosorbent assay of culture supernatant in the time-of-addition assay, YK-FH312 inhibited virus expression in the supernatant when it was added 18 h postinfection. However, Western blot analysis of the cells in the time-of-addition assay revealed that the production of viral proteins in the cells was not inhibited completely by YK-FH312. These results suggest that YK-FH312 might affect the step(s) of virion assembly and/or budding of virions, and this is a novel mechanism of action of an anti-HIV compound.

scholarly journals C–C Chemokines Released by Lipopolysaccharide (LPS)-stimulated Human Macrophages Suppress HIV-1 Infection in Both Macrophages and T Cells

1997 ◽  
Vol 185 (5) ◽  
pp. 805-816 ◽  
Author(s):  
Alessia Verani ◽  
Gabriella Scarlatti ◽  
Manola Comar ◽  
Eleonora Tresoldi ◽  
Simona Polo ◽  
...  
Keyword(s):  
T Cells ◽  
Inhibitory Effect ◽  
Hiv Replication ◽  
Soluble Factors ◽  
Human Macrophages ◽  
Immunodeficiency Virus ◽  
Releasing Factors ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

Human immunodeficiency virus-1 (HIV-1) expression in monocyte-derived macrophages (MDM) infected in vitro is known to be inhibited by lipopolysaccharide (LPS). However, the mechanisms are incompletely understood. We show here that HIV-1 suppression is mediated by soluble factors released by MDM stimulated with physiologically significant concentrations of LPS. LPS-conditioned supernatants from MDM inhibited HIV-1 replication in both MDM and T cells. Depletion of C–C chemokines (RANTES, MIP-1α, and MIP-1β) neutralized the ability of LPS-conditioned supernatants to inhibit HIV-1 replication in MDM. A combination of recombinant C–C chemokines blocked HIV-1 infection as effectively as LPS. Here, we report an inhibitory effect of C–C chemokines on HIV replication in primary macrophages. Our results raise the possibility that monocytes may play a dual role in HIV infection: while representing a reservoir for the virus, they may contribute to the containment of the infection by releasing factors that suppress HIV replication not only in monocytes but also in T lymphocytes.

scholarly journals Induction of APOBEC3 family proteins, a defensive maneuver underlying interferon-induced anti–HIV-1 activity

2006 ◽  
Vol 203 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Gang Peng ◽  
Ke Jian Lei ◽  
Wenwen Jin ◽  
Teresa Greenwell-Wild ◽  
Sharon M. Wahl
Keyword(s):  
Cytidine Deaminase ◽  
Intracellular Protein ◽  
Mrna Editing ◽  
Hiv Replication ◽  
Potent Inducer ◽  
Virion Infectivity Factor ◽  
Immunodeficiency Virus ◽  
Editing Enzyme ◽  
Anti Hiv ◽  
Hiv 1

Apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (APOBEC3G), a cytidine deaminase, is a recently recognized innate intracellular protein with lethal activity against human immunodeficiency virus (HIV). Packaged into progeny virions, APOBEC3G enzymatic activity leads to HIV DNA degradation. As a counterattack, HIV virion infectivity factor (Vif) targets APOBEC3G for proteasomal proteolysis to exclude it from budding virions. Based on the ability of APOBEC3G to antagonize HIV infection, considerable interest hinges on elucidating its mechanism(s) of regulation. In this study, we provide the first evidence that an innate, endogenous host defense factor has the potential to promote APOBEC3G and rebuke the virus-mediated attempt to control its cellular host. We identify interferon (IFN)-α as a potent inducer of APOBEC3G to override HIV Vif neutralization of APOBEC3 proteins that pose a threat to efficient macrophage HIV replication. Our data provide a new dimension by which IFN-α mediates its antiviral activity and suggest a means to render the host nonpermissive for viral replication.

scholarly journals Nucleoside Analog Resistance Caused by Insertions in the Fingers of Human Immunodeficiency Virus Type 1 Reverse Transcriptase Involves ATP-Mediated Excision

2002 ◽  
Vol 76 (18) ◽  
pp. 9143-9151 ◽  
Author(s):  
Paul L. Boyer ◽  
Stefan G. Sarafianos ◽  
Edward Arnold ◽  
Stephen H. Hughes
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ternary Complex ◽  
Nucleoside Analogs ◽  
Wild Type ◽  
Resistance Mutations ◽  
Immunodeficiency Virus ◽  
Azt Resistance ◽  
Hiv 1

ABSTRACT Although anti-human immunodeficiency virus type 1 (HIV-1) therapy has prolonged the lives of patients, drug resistance is a significant problem. Of particular concern are mutations that cause cross-resistance to a particular class of drugs. Among the mutations that cause resistance to several nucleoside analogs are the insertion of amino acids in the fingers subdomain of HIV-1 reverse transcriptase (RT) at positions 69 and 70. These insertions are usually associated with changes in the flanking amino acids and with a change to F or Y at position 215. We have proposed that the T215F/Y mutation makes the binding of ATP to HIV-1 RT more effective, which increases the excision of 3-azido-3′-deoxythymidine-5′-monophosphate (AZTMP) in vitro and increases zidovudine (AZT) resistance in vivo. Although the mechanism of AZT resistance involves enhanced excision, resistance to 3TC involves a block to incorporation of the analog. We measured the effects of fingers insertion mutations on the misincorporation and excision of several nucleoside analogs. RT variants with the amino acid insertions in the fingers and T215Y have a decreased level of misincorporation of ddATP and 3TCTP. These mutants also have the ability to excise AZTMP by ATP-dependent pyrophosphorylysis. However, unlike the classic AZT resistance mutations (M41L/D67N/K70R/T215Y or F/K219E or Q), the combination of the amino acid insertions in the fingers and the T215Y mutation allows efficient excision of ddTMP and d4TMP, even when relatively high levels of deoxynucleoside triphosphates are present in the reaction. Although the dideoxynucleoside analogs of other nucleosides were excised more slowly than AZTMP, ddTMP, and d4TMP, the mutants with the fingers insertion and T215Y excised all of the nucleoside analogs that were tested more efficiently than wild-type RT or a mutant RT carrying the classical AZT resistance mutations. In the ternary complex (RT/template-primer/dNTP), the presence of the bound dNTP prevents the end of the primer from gaining access to the nucleotide binding site (N site) where excision occurs. Gel shift analysis showed that the amino acid insertions in the fingers destabilized the ternary complex compared to wild-type HIV-1 RT. If the ternary complex is unstable, the end of the primer can gain access to the N site and excision can occur. This could explain the enhanced excision of the nucleoside analogs.

Sign in / Sign up

Export Citation Format

Share Document