Immunological discrimination of diverse forms of human alpha 1-proteinase inhibitor.
The immunodiffusion cross-reactivity and competitive inhibition ELISA assays were used for immunological differentiation of latent form, cleaved form and guanidinium hydrochloride (GuHCl) induced polymer of human alpha 1-proteinase inhibitor (alpha 1-PI). Under the conditions studied, the differences between latent form and GuHCl-induced polymers of the inhibitor in terms of immunological response were estimated to amount to about 30% and differences between latent and cleaved alpha 1-PI to about 50%. The immunodiffusion and ELISA data for citrate-induced polymers suggest that in their structure the latent molecule is involved. On the basis of competitive inhibition data, we suggest that the alpha 1-PI protein polymerisation involves insertion of the reactive-site loop (RSL) into the A-sheet under mild conditions and that in the latent form of the inhibitor RSL is incompletely inserted into the A-sheet.
Wawrzos
I
I
Agriculture University, Department of Biochemistry, Cracow, Poland.
Kitagawa
Y
Y
Kołoczek
H
H
D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007106:Immune Sera; D005779:Immunodiffusion; D000515:alpha 1-Antitrypsin / Q000276:immunology*
D007106:Immune Sera; D000515:alpha 1-Antitrypsin