Localization of a serine proteinase inhibitor, B-43, in the bovine pancreas

Masahiro Nishibori, Naoki Nakaya, Aiji Ohtsuka, Takuro Murakami, Kiyomi Saeki

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


B-43, a serine proteinase inhibitor belonging to the ovalbumin branch of the serpin superfamily, was purified and cloned from bovine brain. Since [35S]-labeled B-43 forms SDS-stable complexes with pancreatic serine proteinases, trypsin, α-chymotrypsin, and kallikrein, it has been suggested that B-43 is capable of inhibiting these serine proteinases and that B-43 may be present in the pancreas. In the present study, we investigated the localization of B-43 in the bovine pancreas immunohistochemically and examined the effect of B-43 on the amidolytic activities of pancreatic serine proteinases. Strong B-43-1ike immunoreactivity was localized in acinat cells, especially in the basal sides of the cells where the rough endoplasmic reticulum is located. The nuclei of the subpopulation of acinar cells were also immunoreactive for B-43. The recombinant glutathione S-transferase-B-43 fusion protein inhibited the amidolytic activity of trypsin and, to a lesser extent, α-chymotrypsin and kallikrein, but not elastase. These results suggest a role of B-43 in regulating serine proteinases both in the cytoplasm and the nucleus.

Original languageEnglish
Pages (from-to)51-56
Number of pages6
JournalHistochemistry and Cell Biology
Issue number1
Publication statusPublished - 1998

ASJC Scopus subject areas

  • Histology
  • Molecular Biology
  • Medical Laboratory Technology
  • Cell Biology


Dive into the research topics of 'Localization of a serine proteinase inhibitor, B-43, in the bovine pancreas'. Together they form a unique fingerprint.

Cite this