Human immunodeficiency virus 1 protease expressed in Escherichia coli behaves as a dimeric aspartic protease.
Recombinant human immunodeficiency virus 1 (HIV-1) protease, purified from a bacterial expression system, processed a recombinant form of its natural substrate, Pr55gag, into protein fragments that possess molecular weights commensurate with those of the virion gag proteins. Molecular weights of the protease obtained under denaturing and nondenaturing conditions (11,000 and 22,000, respectively) and chemical crosslinking studies were consistent with a dimeric structure for the active enzyme. The protease appropriately cleaved the nonapeptide Ac-Arg-Ala-Ser-Gln-Asn-Tyr-Pro-Val-Val-NH2 between the tyrosine and proline residues. HIV-1 protease was sensitive to inactivators of the aspartic proteases. The aspartic protease inactivator 1,2-epoxy-3-(4-nitrophenoxy)propane produced irreversible, time-dependent inactivation of the protease. The pH-dependent kinetics of this inactivator were consistent with the requirement of an unprotonated carboxyl group in the active site of the enzyme, suggesting that HIV-1 protease is also an aspartic protease.
Meek
T D
TD
Department of Medicinal Chemistry, Smith Kline & French Laboratories, King of Prussia, PA 19406.
Dayton
B D
BD
Metcalf
B W
BW
Dreyer
G B
GB
Strickler
J E
JE
Gorniak
J G
JG
Rosenberg
M
M
Moore
M L
ML
Magaard
V W
VW
Debouck
C
C
D016282:Aspartic Acid Endopeptidases; D001665:Binding Sites; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004852:Epoxy Compounds / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015683:Gene Products, gag; D006678:HIV / Q000201:enzymology* / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009596:Nitrophenols / Q000494:pharmacology; D009842:Oligopeptides / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D011480:Protease Inhibitors; D011994:Recombinant Proteins / Q000378:metabolism*; D012191:Retroviridae Proteins; D013379:Substrate Specificity
D004852:Epoxy Compounds; D015683:Gene Products, gag; D046911:Macromolecular Substances; D009596:Nitrophenols; D009842:Oligopeptides; D010446:Peptide Fragments; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D012191:Retroviridae Proteins; C007606:1,2-epoxy-3-(p-nitrophenoxy)propane; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases