Study of Antigenic properties of Human immunodeficiency Virus NEF protein Recombinant Analog

Protein p27/p25 is a product of HIV nef gene and is a multifunctional factor of HIV pathogenicity. Antigenic properties of recombinant NEF polypeptide which includes N-terminal fragment of HIV-1 p27 protein fused to E. coli ß-galactosidase were studied by serological and virological methods. The interaction was shown between recombinant NEF antigen and serums of HIV-positive individuals by ELISA, Western blot and line immunoassay. There was no interaction with sera of healthy individuals. The antigen specificity of recombinant antigen was shown in the reactions with commercial HIV-1 p27/p25 protein analog and with polyclonal antibodies to synthetic peptides corresponding to N-, C-terminal regions of HIV-1 p27/p25 protein. The interaction between IgG of rabbits immunized with recombinant NEF antigen and viral antigens was shown by indirect immunofluorescence and neutralizing assays. Thus it was proven the possibility of using recombinant NEF protein as an antigen for diagnostic and experimental purposes.

Kinesin-related proteins in eukaryotic flagella

To identify kinesin-related proteins that are important for ciliary and eukaryotic flagellar functions, we used affinity-purified, polyclonal antibodies to synthetic peptides corresponding to conserved sequences in the motor domain of kinesin (Sawin et al. (1992) J. Cell Sci. 101, 303–313). Using immunoblot analysis, two antibodies to distinct sequences (LNLVDLAGSE, ‘LAGSE’ and, HIPYRESKLT, ‘HIPYR’) reveal a family of proteins in flagella and axonemes isolated from Chlamydomonas. Similar analysis of axonemes from mutant Chlamydomonas strains or fractionated axonemes indicates that none of the immunoreactive proteins are associated with dynein arm or spoke structures. In contrast, one protein, approximately 110 kDa, is reduced in axonemes from mutant strains defective in the central pair apparatus. Immunoreactive proteins with masses of 96 and 97 kDa (the ‘97 kDa’ proteins) are selectively solubilized from isolated axonemes in 10 mM ATP. The 97 kDa proteins co-sediment in sucrose gradients at about 9 S and bind to axonemes or purified microtubules in a nucleotide-dependent fashion characteristic of kinesin. These results reveal that flagella contain kinesin-related proteins, which may be involved in axonemal central pair function and flagellar motility, or directed transport involved in morphogenesis or mating responses in Chlamydomonas.

Antibodies to synthetic peptides based on band 3 motifs react specifically with Plasmodium falciparum (humanmalaria)-infected erythrocytes and block cytoadherence

SUMMARYRabbit polyclonal and mouse monoclonal antibodies (Mabs) prepared against synthetic peptides patterned on exofacialloops 3 (amino acids 546–555) and 7 (821–834) of the human anion transport protein band 3 inhibited the cytoadherence of Plasmodium falciparum-infected erythrocytes to C32 amelanotic melanoma cells. Mabs directed against exofacial loop4 (amino acids 628–642) did not inhibit adherence to a significant degree. The murine Mabs recognized only P. falciparum- infected erythrocytes suggesting that the epitopes of loops 3, 4 and 7 are normally cryptic in uninfected erythrocytes.