Natl Conf Hum Retroviruses Relat Infect (1st). 1993 Dec 12-16;:126.
Protective antigen (PA), a protein component from anthrax toxin, must be
cleaved in order to intoxicate cells. After binding to its receptor, a
cell associated protease recognizes and cleaves PA after the amino acid
sequence RKKR. We used cassette mutagenesis to replace residues 164167
(RKKR) of PA with five different sequences expected to be recognized by
HIV-1 protease. The resulting recombinant proteins were expressed in
Bacillus anthraces and purified from the culture supernatant (table: see
text). Recombinant HIV-1 protease was used to digest each PA mutant in
vitro. PAHIV No's 1, 2, 3 and 4 were all cleaved by the protease while
PAHIV No. 5 was not. Cleavage was apparent in as little as 5 min. PAHIV
No. 3 was cleaved the most efficiently followed by PAHIV No. 1 and PAHIV
No. 2. When PA or PAHIV proteins were incubated with the HIV-1 protease
for more than 60 min an unexpected second cleavage occurred. This may
represent cleavage of PA and PAHIV proteins at residues 256VAAYPIVHV264.
In addition to potential anti- viral applications, PAHIV proteins may be
valuable tools for studying the action of the HIV-1 protease and its
inhibitors in the context of a whole protein.
Amino Acid Sequence Bacterial Toxins/*METABOLISM HIV
Protease/*METABOLISM HIV-1/*ENZYMOLOGY Molecular Sequence Data
Mutagenesis, Insertional Recombinant Proteins/METABOLISM ABSTRACT