Interaction of the octapeptide angiotensin II with a high-affinity single-chain Fv and with peptides derived from the antibody paratope.

The amino-acid sequence of the very high-affinity anti-angiotensin II monoclonal antibody 4D8 was predicted from the nucleotide sequence of the heavy and light chain variable genes. The single-chain variable fragment (scFv) was constructed and expressed in Escherichia coli as a soluble protein and at the surface of the filamentous M13 phage and was compared with the full-length antibody (Ab). The scFv showed the same specificity profile and affinity constant as the intact antibody (5.

Selective recognition of M235T angiotensinogen variants and their determination in human plasma by monoclonal antibody-based immunoanalysis.

The common M235T mutation of human angiotensinogen has been shown to be associated with a 10-20% increase in plasma angiotensinOgen level and increased frequency of essential and pregnancy-induced hypertension. The detection of such a common factor in the plasma of individuals at risk could be a useful tool for modern molecular-based medicine. The recognition of M235T variants was investigated using four monoclonal antibodies (mAbs) directed against human angiotensinogen; two immunometric assays were developed.

New monoclonal antibodies directed against the propart segment of human prorenin as a tool for the exploration of prorenin conformation.

Six monoclonal antibodies (MAbs) directed against human prorenin were produced by immunizing BALB/c mice with a peptide corresponding to the sequence (-17 to +9) of prorenin. The new MAbs were screened for their ability to first bind to the immobilized peptide and then to prorenin previously captured by an anti-total renin MAb. The specificity of the MAbs was confirmed by the total lack of binding to active renin.

Direct, simplified, and sensitive assay of angiotensin II in plasma extracts performed with a high-affinity monoclonal antibody.

A very simple, fast, and sensitive RIA of angiotensin (Ang) II has been developed, based on a monoclonal antibody with high affinity and specificity, making possible the direct measurement of circulating Ang II in human plasma after solid-phase extraction. The purified monoclonal antibody 4D8 has an association constant of 1.3 x 10(11) L/mol with Ang II and a cross-reactivity of < 1% for Ang I.

Two-site direct immunoassay specific for active renin.

A sensitive immunoradiometric assay, without an enzymatic step and specific for active human renin, was developed with use of two monoclonal antibodies (MAbs). In this assay system, the first MAb was coupled to magnetic beads (Magnogel); the second one, directed against the active form of the enzyme, was radiolabeled with 125I. The specificity of this assay was demonstrated in experiments measuring the active plasma renin concentration in the presence or absence of inactive renin.

Production and partial characterization of monoclonal antibodies against 3,3',5-triiodo-L-thyronine.

Spleen cells of Biozzi HL mouse (selection V) immunized with bovine albumin-triiodothyronine conjugate were fused with P3-X63-Ag8.653 mouse myeloma cells. Thirteen monoclonal antibodies, selected by an enzyme-linked immunosorbent assay and a radioimmunoassay, were produced in mouse ascites fluid, purified and analyzed.

Measurement of active renin by the 4G1 anti-human renin monoclonal antibody.

Three monoclonal human renin antibodies have been selected to settle two immunoradiometric assays of human plasma renin (IRMA). The first pair of antibodies 3E8-4G1 recognizes exclusively active renin (AR), as demonstrated by the lack of increase either of the number of AR molecules or the renin enzymatic activity, when plasma is set free of inactive renin (IR) by immunoaffinity chromatography with human renin prosegment monoclonal antibody. The second pair of monoclonal antibodies 4E1-3E8 gives results which are very significantly correlated to those obtained with the 3E8-4G1 pair after trypsin activation.

Analysis of inactive renin by renin profragment monoclonal antibodies.

Two peptides were synthesized, corresponding to the sequences (-19 to -7) and (-26 to -17) of the prorenin prosegment. Monoclonal antibodies were raised to these sequences and used to characterize human plasma inactive renin. Only anti (-19 to -7) reacted with inactive renin, as measured by direct assay or affinity chromatography.

New monoclonal antibodies directed against human renin. Powerful tools for the investigation of the renin system.

Monoclonal antibodies directed against human renin were obtained by the fusing of myeloma cells with spleen cells from Balb/c or high-responder Biozzi mice injected with pure tumoral or highly purified renal renin. These procedures resulted in the production of seven stable monoclonal antibodies to human renin. Antibodies in the hybridoma culture medium were screened by binding to pure iodinated renin or insolubilized renin in a solid phase assay.