1JRT

HEMIACETAL COMPLEX BETWEEN LEUPEPTIN AND TRYPSIN

Summary for 1JRT

• Entry DOI: 10.2210/pdb1jrt/pdb
• Related PRD ID: PRD_000216
• Descriptor: TRYPSIN, LEUPEPTIN, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: hydrolase, serine protease, digestion, pancreas, zymogen, hydrolase (serine protease), hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Bos taurus (cattle); More
• Cellular location: Secreted, extracellular space: P00760
• Total number of polymer chains: 2
• Total formula weight: 23793.94

Authors

Kurinov, I.V.,Harrison, R.W. (deposition date: 1996-02-07, release date: 1996-10-14, Last modification date: 2024-11-20)

Primary citation

Kurinov, I.V.,Harrison, R.W.
Two crystal structures of the leupeptin-trypsin complex.
Protein Sci., 5:752-758, 1996

PubMed Abstract: Three-dimensional structures of trypsin with the reversible inhibitor leupeptin have been determined in two different crystal forms. The first structure was determined at 1.7 A resolution with R-factor = 17.7% in the trigonal crystal space group P3(1)21, with unit cell dimensions of a = b = 55.62 A, c = 110.51 A. The second structure was determined at a resolution of 1.8 A with R-factor = 17.5% in the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions of a = 63.69 A, b = 69.37 A, c = 63.01 A. The overall protein structure is very similar in both crystal forms, with RMS difference for main-chain atoms of 0.27 A. The leupeptin backbone forms four hydrogen bonds with trypsin and a fifth hydrogen bond interaction is mediated by a water molecule. The aldehyde carbonyl of leupeptin forms a covalent bond of 1.42 A length with side-chain oxygen of Ser-195 in the active site. The reaction of trypsin with leupeptin proceeds through the formation of stable tetrahedral complex in which the hemiacetal oxygen atom is pointing out of the oxyanion hole and forming a hydrogen bond with His-57.

PubMed: 8845765

Experimental method

X-RAY DIFFRACTION (1.7 Å)