Inhibition of HIV-1 Replication by Disruption of the Processing of the Viral Capsid-Spacer Peptide 1 Protein

Abstract

Inhibition of HIV-1 replication by disrupting the processing of the viral Gag capsid (CA) protein (p24) from the CA-spacer peptide 1 (SP1) protein precursor (p25) is disclosed. Amino acid sequences containing a mutation in the Gag p25 protein, with the mutation resulting in a decrease in the inhibition of processing of p25 to p24 by dimethylsuccinyl betulinic acid or dimethylsuccinyl betulin, polynucleotides encoding such mutated sequences and antibodies that selectively bind such mutated sequences are also included. Methods of inhibiting, inhibitory compounds and methods of discovering inhibitory compounds that target proteolytic processing of the HIV Gag protein are included. In one embodiment, such compounds inhibit the interaction of the HIV protease enzyme with Gag by binding to Gag rather than to the protease enzyme. In another embodiment, viruses or recombinant proteins that contain mutations in the region of the Gag proteolytic cleavage site can be used in screening assays to identify compounds that target proteolytic processing.

1 . A method of determining if an individual is infected with HIV-1 that is susceptible to inhibition by a compound that inhibits p25 (CA-SP1) processing to p24 (CA), comprising taking a sample of blood from the patient, and determining whether HIV-1 gag in said sample is susceptible to inhibition of p25 (CA-SP1) processing to p24 (CA) by the compound. 
     
     
         2 . The method of  claim 1 , which comprises determining whether said HIV-1 gag contains a mutation that results in a decrease in inhibition of processing by said compound. 
     
     
         3 . The method of  claim 2 , which comprises genotyping said HIV-1 gag. 
     
     
         4 . The method of  claim 3 , which comprises genotyping the region of the CA-SP1 cleavage site. 
     
     
         5 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of Ala to Val at a position corresponding to residue 364 of HIV-1 Gag (residue 1 of SP1). 
     
     
         6 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of Ala to Val at a position corresponding to residue 366 of HIV-1 Gag (residue 3 of SP1). 
     
     
         7 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of H is to Tyr at a position corresponding to residue 358 of HIV-1 Gag. 
     
     
         8 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of Leu to Phe at a position corresponding to residue 363 of HIV-1 Gag (the C-terminal residue of CA). 
     
     
         9 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of Leu to Met at a position corresponding to residue 363 of HIV-1 Gag (the C-terminal residue of CA). 
     
     
         10 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a deletion of the residue at a position corresponding to residue 370 of HIV-1 Gag (position 7 of SP1). 
     
     
         11 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of Ala to Val at a position corresponding to residue 366 of HIV-1 Gag (position 3 of SP1) and a Ser residue at a position corresponding to residue 357 of HIV-1 Gag. 
     
     
         12 . The method of  claim 3 , which comprises determining whether said HIV-1 gag encodes a substitution of Ala to Val at a position corresponding to residue 366 of HIV-1 Gag (position 3 of SP1) and a substitution of Gly to Ser at a position corresponding to residue 357 of HIV-1 Gag.