Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

To map the determinants of the lack of susceptibility of feline immunodeficiency virus (FIV) reverse transcriptase (RT) to anti human immunodeficiency virus type 1 (HIV-1) non-nucleoside RT inhibitors (NNRTIs), a variety of chimeric HIV-1/FIV RTs were constructed. The majority of chimeric RTs had an affinity (Km) for their natural substrates comparable with that of the wild-type HIV-1 and FIV RTs, but their catalytic efficacy was decreased. Whereas HIV-1 RT could be made entirely insensitive to NNRTIs by exchanging the amino acid sequence 97 through 205 of FIV RT, none of the reverse FIV/HIV-1 RT chimeras gained susceptibility to NNRTIs. The amino acids that are thought to be involved in NNRTI susceptibility and that are different from those in HIV-1 RT have also been introduced in FIV RT. These mutant RTs gained virtually no susceptibility to efavirenz or capravirine. Vice versa, when these HIV-1-specific amino acids were replaced by their FIV RT counterparts in HIV-1 RT, susceptibility to the NNRTIs was lost. Thus, replacing segments or substituting relevant amino acids in FIV RT by their HIV-1 RT counterparts did not suffice to make FIV RT sensitive toward NNRTIs and was often accompanied by a decrease or even total loss of polymerase activity. It is postulated that, in contrast to the results found for HIV-1/HIV-2 RT chimeras and supported by the crystal structure of HIV-2 RT, there exist significant differences in the structure and/or flexibility of FIV RTs that may prevent NNRTIs from interacting with the FIV RT.

Original publication

DOI

10.1124/mol.65.1.244

Type

Journal article

Journal

Molecular pharmacology

Publication Date

01/2004

Volume

65

Pages

244 - 251

Addresses

Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium.

Keywords

Animals, Cats, Humans, Immunodeficiency Virus, Feline, HIV-1, Sulfur Compounds, Foscarnet, Imidazoles, Nevirapine, RNA-Directed DNA Polymerase, Recombinant Fusion Proteins, Deoxyguanine Nucleotides, Reverse Transcriptase Inhibitors, Anti-HIV Agents, Species Specificity, Amino Acid Sequence, Sequence Homology, Amino Acid, Kinetics, Catalysis, Molecular Sequence Data, HIV Reverse Transcriptase, Dideoxynucleotides