Details

Autor(en) / Beteiligte

• Shimokawa, Y
• Abe, O
• Kuromizu, K

Titel

Fluorescence labeling of a single sulfhydryl group in human plasma alpha sub(1)-proteinase inhibitor and characterization of the labeled inhibitor

Ist Teil von

• Journal of biochemistry (Tokyo), 1986-01, Vol.100 (3), p.563-570

Erscheinungsjahr

1986

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A single cysteine residue present in human plasma alpha sub(1)-proteinase inhibitor was labeled with a fluorescent sulfhydryl reagent, N-iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine. The resulting fluorescent inhibitor retained nearly full inhibitory activity and formed complexes with bovine chymotrypsin, porcine pancreatic elastase, and bovine trypsin as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Association rate constants for the interactions of the labeled inhibitor with the proteinases were determined to be 1.5 ( plus or minus 0.4) x 10 super(6), 3.3 ( plus or minus 0.3) x 10 super(5), and 1.4 ( plus or minus 0.3) x 10 super(5) M super(-1) multiplied by s super(-1) for chymotrypsin, elastase, and trypsin, respectively. Fluorescence emission spectra of the labeled inhibitor in the absence and presence of each proteinase were also examined, and little difference was observed between them.