Native Bovine Aprotinin / Pancreatic Trypsin Inhibitor (BPTI) – Research Use Only

Native bovine aprotinin, also known as bovine pancreatic trypsin inhibitor (BPTI), is a well‑characterized Kunitz‑type serine protease inhibitor widely used in biochemical, enzymatic, and structural biology research. BPTI binds tightly to trypsin and related serine proteases, making it a powerful tool for studying protein folding, protease regulation, enzyme kinetics, conformational stability, and disulfide‑bonded protein architecture. Its compact 58‑residue structure and three‑disulfide‑bond topology have made BPTI one of the most extensively studied model proteins in biophysics and protein‑folding research.

This product is supplied as native bovine BPTI in multiple size formats to support assay development, mechanistic studies, inhibitor profiling, and structural workflows.

Available Sizes

Specifications

Scientific Overview

BPTI is a classical model protein for studying protein folding pathways, disulfide bond formation, conformational stability, and protease–inhibitor interactions. Its small size, rigid structure, and well‑defined folding intermediates have made it foundational in the fields of protein chemistry and biophysics. Native BPTI binds trypsin and related serine proteases with high affinity, blocking proteolytic activity and enabling precise control of enzymatic reactions in vitro.

Because of its stability and well‑characterized folding landscape, BPTI is frequently used in:

• Protein folding and misfolding studies
• Disulfide‑bond engineering and redox biology
• Protease inhibition assays
• Structural biology (NMR, crystallography)
• Biophysical characterization (CD, DSC, kinetics)
• Benchmarking computational protein‑folding models

Usage & Handling Guidance

Reconstitute in sterile buffer to the desired concentration. Avoid repeated freeze–thaw cycles by aliquoting after reconstitution. Maintain samples on ice during assay setup and use low‑binding tubes for optimal recovery.

• Recommended working concentrations: 1–100 µg/mL depending on assay
• Storage (powder): −20 °C
• Storage (reconstituted): −80 °C
• Handling: Avoid repeated freeze–thaw cycles
• Compatibility: Enzyme assays, folding studies, structural workflows

What You Get

• Native bovine pancreatic trypsin inhibitor (BPTI), powder
• Available in 5 mg, 10 mg, 25 mg, 50 mg, and 100 mg formats
• High‑purity biotechnology‑grade preparation
• Batch‑specific documentation available upon request
• For research use only (RUO)

Frequently Asked Questions

• Is this product native or recombinant?
  This is native bovine pancreatic trypsin inhibitor (BPTI), purified from bovine sources.
• What proteases does BPTI inhibit?
  Primarily trypsin and related serine proteases.
• Is BPTI suitable for folding and stability studies?
  Yes — BPTI is one of the most widely used model proteins for folding pathway analysis.
• What is the typical molecular weight?
  Approximately 6.5 kDa for native BPTI.
• How should the product be stored?
  Store powder at −20 °C; store reconstituted aliquots at −80 °C.
• Is this product suitable for diagnostic or therapeutic use?
  No. This reagent is intended strictly for laboratory, academic, and government research use only (RUO).

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References

• Li R, Battiste JL, Woodward C. Native-like interactions favored in the unfolded bovine pancreatic trypsin inhibitor have different roles in folding Biochemistry. 2002 Feb 19;41(7):2246-53.
• Ang MJ, Lim HA, Poulsen A, Wee JL, Ng FM, Joy J, Hill J, Chia CS. Miniature bovine pancreatic trypsin inhibitors (m-BPTIs) of the West Nile virus NS2B-NS3 protease J Enzyme Inhib Med Chem. 2016;31(sup2):194-200.
• Kuroda Y, Kim PS. Folding of bovine pancreatic trypsin inhibitor (BPTI) variants in which almost half the residues are alanine J Mol Biol. 2000 May 5;298(3):493-501.
• Tulla-Puche J, Getun IV, Woodward C, Barany G. Native-like conformations are sampled by partially folded and disordered variants of bovine pancreatic trypsin inhibitor Biochemistry. 2004 Feb 17;43(6):1591-8.
• Weissman JS, Kim PS. Kinetic role of nonnative species in the folding of bovine pancreatic trypsin inhibitor Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9900-4.
• Hao MH, Pincus MR, Rackovsky S, Scheraga HA. Unfolding and refolding of the native structure of bovine pancreatic trypsin inhibitor studied by computer simulations Biochemistry. 1993 Sep 21;32(37):9614-31.
• Marks CB, Vasser M, Ng P, Henzel W, Anderson S. Production of native, correctly folded bovine pancreatic trypsin inhibitor by Escherichia coli J Biol Chem. 1986 Jun 5;261(16):7115-8.
• Chang JY. Distinct folding pathways of two homologous disulfide proteins: bovine pancreatic trypsin inhibitor and tick anticoagulant peptide Antioxid Redox Signal. 2011 Jan 1;14(1):127-35.
• Oddone R, Barra D, Amiconi G, Ascenzi P, Tarricone C, Bolognesi M, Bortolotti F, Menegatti E. Binding of native and [homoserine lactone-52]-52,53-seco-bovine basic pancreatic trypsin inhibitor (Kunitz inhibitor) to porcine pancreatic beta-kallikrein-B and bovine alpha-chymotrypsin: thermodynamic study J Mol Recognit. 1994 Mar;7(1):39-46.