Radiolabeling of the biologically active peptide 163-171 of human interleukin-1 beta.

N-succinimidyl[2,3-3H]propionate was used for the radiolabeling of the biologically active peptide fragment 163-171 of human interleukin-1 beta (VQGEESNDK). Suitable reaction conditions were studied to obtain useful labeling of the molecule. A mixture of mono- (70%) and bi- (30%) propionyl derivatives was obtained with a total 3H specific activity of 87 Ci/mmol of peptide.

Studies of the antigenic structure of two cross-reacting proteins, pertussis and cholera toxins, using synthetic peptides.

Peptide fragments of pertussis toxin subunit 1 (PT-S1) have been synthesized in order to investigate their antigenic and immunogenic activity, and to evaluate their possible use as components of a new vaccine. Two peptides (sequence 73-82, EAERAGRGTG and sequence 107-116, YVDTYGDNAG) were selected for their predictable exposure on the surface of the molecule, and a third (8-18, YRYDSRPPEDV) for its homology with the sequence 6-16 of cholera toxin subunit A (CT-A 6-16) (YRADSRPPDEI). Antipeptide polyclonal antibodies produced in rabbits, were tested in different immunoassays for their ability to interact with toxin proteins.

Influence of the peptide insolubilization method on detection of anti-peptide antibodies in ELISA. Evaluation of nonspecific interactions.

Different methods of peptide insolubilization in solid phase were compared in ELISA, to verify the influence of the peptide antigen presentation in the interaction with related antibodies. Our studies were performed using as model the peptide fragment 163-171 of human Interleukin 1 beta, and polyclonal or monoclonal anti-peptide antibodies. It was found that the peptide, N-terminally linked to a protein carrier before the adsorption on microtiter wells, interacted with specific polyclonal and monoclonal antibodies with high sensitivity and specificity.