The structural and aggregation properties of the synthetic C-terminal half (104-mer) polypeptide from HIV p24gag resemble those of full-length protein.
The aggregation and structural properties of the synthetic C-terminal half [Ala330, Ala350(270-373; 104-mer)] polypeptide from HIV-1 p24gag were studied. In concentrated solutions the synthetic polypeptide aggregated to tetramers which, upon dilution, gave a mixture of monomeric and dimeric and dimeric species. These results correlated well with the in vitro aggregation properties of recombinant p24. The tetrameric form of the synthetic polypeptide had a pI which differed by about four units from that of the mixture of monomeric and dimeric species. CD studies indicated that the latter contained, in aqueous solutions, a compact molecule lacking, however, a defined tertiary structure. Addition of MeOH to aqueous solutions of both tetramer and monomer/dimer mixture induced a more defined structure, which was assigned to that of an alpha + beta protein in agreement with secondary structure predictions. A model of the dimeric form of the 104-mer, which takes into account the results presented here and those from a study on the specificity of a set of anti-104-mer MoAbs, is presented. Finally, the results indicated that the structure of the 104-mer in its dimeric form is similar to that adopted by the same sequence when part of full-length p24.
Ball
H L
HL
Italfarmaco Research Centre, Cinisello Balsamo, Milan, Italy.
Chan
A W
AW
Gibbons
W A
WA
Coates
A R
AR
Mascagni
P
P
D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002942:Circular Dichroism; D016655:HIV Core Protein p24 / Q000737:chemistry*; D015497:HIV-1; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D016415:Sequence Alignment
D016655:HIV Core Protein p24; D010446:Peptide Fragments; D010455:Peptides