Sandbox 47
From Proteopedia
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<scene name='Sandbox_47/63/1'>63</scene> has hydrophobic interaction with Pro 2 and one hydrogen bond with Arg 1. Ligand <scene name='Sandbox_47/Ligand_64/1'>64</scene> has hydrophobic interaction with Cys 14. | <scene name='Sandbox_47/63/1'>63</scene> has hydrophobic interaction with Pro 2 and one hydrogen bond with Arg 1. Ligand <scene name='Sandbox_47/Ligand_64/1'>64</scene> has hydrophobic interaction with Cys 14. | ||
| - | BPTI has both a <scene name='Sandbox_47/Primary_loop/1'>primary</scene> and a <scene name='Sandbox_47/Secondary_loop/1'>secondary loop</scene> involved in the binding and inhibition of Trypsin. This particular mutant of BPTI contains several residue substitutions within these loop, including a substitution at <scene name='Sandbox_47/Lys_mutation/1'>residue 15</scene>, which is is normally Lys but has been replaced by Arg. This basic Lys normally binds to the active site of Trypsin and is therefore important to the inhibition of the protease. This mutant also has <scene name='Sandbox_47/Thr11_sub/1'>Thr11Ala</scene>, Pro13Ala, and Met52Leu substitutions. Altogether these substitutions reduce BPTI's association constant by approximately 30 times (Czapinska et al,1999). | + | BPTI has both a <scene name='Sandbox_47/Primary_loop/1'>primary</scene> and a <scene name='Sandbox_47/Secondary_loop/1'>secondary loop</scene> involved in the binding and inhibition of Trypsin. This particular mutant of BPTI contains several residue substitutions within these loop, including a substitution at <scene name='Sandbox_47/Lys_mutation/1'>residue 15</scene>, which is is normally Lys but has been replaced by Arg. This basic Lys normally binds to the active site of Trypsin and is therefore important to the inhibition of the protease. This mutant also has <scene name='Sandbox_47/Thr11_sub/1'>Thr11Ala</scene>, <scene name='Sandbox_47/Sub/1'>Pro13Ala</scene>, and Met52Leu substitutions. Altogether these substitutions reduce BPTI's association constant by approximately 30 times (Czapinska et al,1999). |
Resources: | Resources: | ||
Czapinska, H., Otlewski, J., Krzywda, S., Sheldrick, G.M, Jaskilski, M. (1999) "High-resolution structure of bovine trypsin inhibitor with altered binding loop sequence." J. Mol. Biol. 295:1237 | Czapinska, H., Otlewski, J., Krzywda, S., Sheldrick, G.M, Jaskilski, M. (1999) "High-resolution structure of bovine trypsin inhibitor with altered binding loop sequence." J. Mol. Biol. 295:1237 | ||
Revision as of 14:30, 30 October 2010
| Please do NOT make changes to this Sandbox. Sandboxes 30-60 are reserved for use by Biochemistry 410 & 412 at Messiah College taught by Dr. Hannah Tims during Fall 2012 and Spring 2013. |
Bovine Pancreatic Trypsin Inhibitor (BPTI) Mutant with Altered Binding Loop Sequence
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BPTI is a single chain polypeptide with 58 amino acids which inhibits the serine protease Trypsin. It's secondary structure includes one and . The beta sheet consists of (Ile18 to Asn 24 and Leu 29 to Tyr 35) with a consisting of four residues (Ala 25, Lys 26, Ala 27, Gly 28). Alpha helix is 4 residues (Asp 3 to Cys 6), and is 8 residues (Ala 48 to Cys 55). There are three intrachain disulfide bonds in this polypeptide, one between , one between , and one between . These are important for BPTI's stability and its ability to withstand the harsh conditions of the digestive system. This protein has a (gray) with polar and charged residues (purple) extending mostly on the . The N-terminus and C-terminus are in contact through a salt bridge. BPTI interacts with 98 as well as 4 . Ligand binds the protein through hydrophobic interactions between Glu 7, Lys 7, and Phe 41, as well as through 3 hydrogen bonds to Arg 42. Three water molecules are also interact with this ligand. Ligand has hydrophobic interaction with Ala 40, two hydrogen bonds with Arg 20, and one hydrogen bond with Tyr 35. Ligand has hydrophobic interaction with Pro 2 and one hydrogen bond with Arg 1. Ligand has hydrophobic interaction with Cys 14.
BPTI has both a and a involved in the binding and inhibition of Trypsin. This particular mutant of BPTI contains several residue substitutions within these loop, including a substitution at , which is is normally Lys but has been replaced by Arg. This basic Lys normally binds to the active site of Trypsin and is therefore important to the inhibition of the protease. This mutant also has , , and Met52Leu substitutions. Altogether these substitutions reduce BPTI's association constant by approximately 30 times (Czapinska et al,1999).
Resources: Czapinska, H., Otlewski, J., Krzywda, S., Sheldrick, G.M, Jaskilski, M. (1999) "High-resolution structure of bovine trypsin inhibitor with altered binding loop sequence." J. Mol. Biol. 295:1237
