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Bovine Pancreatic Ribonuclease (bovine + pancreatic_ribonuclease)
Selected AbstractsStructure of bovine pancreatic ribonuclease complexed with uridine 5,-monophosphate at 1.60,Å resolutionACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2010Steven B. Larson Bovine pancreatic ribonuclease A (RNase A) was crystallized from a mixture of small molecules containing basic fuchsin, tobramycin and uridine 5,-monophosphate (U5P). Solution of the crystal structure revealed that the enzyme was selectively bound to U5P, with the pyrimidine ring of U5P residing in the pyrimidine-binding site at Thr45. The structure was refined to an R factor of 0.197 and an Rfree of 0.253. [source] Solution NMR evidence for a cis Tyr-Ala peptide group in the structure of [Pro93Ala] bovine pancreatic ribonuclease APROTEIN SCIENCE, Issue 2 2000Ying Xiong Abstract Proline peptide group isomerization can result in kinetic barriers in protein folding. In particular, the cis proline peptide conformation at Tyr92-Pro93 of bovine pancreatic ribonuclease A (RNase A) has been proposed to be crucial for chain folding initiation. Mutation of this proline-93 to alanine results in an RNase A molecule, P93A, that exhibits unfolding/refolding kinetics consistent with a cis Tyr92-Ala93 peptide group conformation in the folded structure (Dodge RW, Scheraga HA, 1996, Biochemistry 35:1548,1559). Here, we describe the analysis of backbone proton resonance assignments for P93 A together with nuclear Overhauser effect data that provide spectroscopic evidence for a type VI ,-bend conformation with a cis Tyr92-Ala93 peptide group in the folded structure. This is in contrast to the reported X-ray crystal structure of [Pro93Gly]-RNase A (Schultz LW, Hargraves SR, Klink TA, Raines RT, 1998, Protein Sci 7:1620,1625), in which Tyr92-Gly93 forms a type-II ,-bend with a trans peptide group conformation. While a glycine residue at position 93 accommodates a type-II bend (with a positive value of ø93), RNase A molecules with either proline or alanine residues at this position appear to require a cis peptide group with a type-VI ,-bend for proper folding. These results support the view that a cis Pro93 conformation is crucial for proper folding of wild-type RNase A. [source] Retardation of the unfolding process by single N-glycosylation of ribonuclease A based on molecular dynamics simulationsBIOPOLYMERS, Issue 2 2008Youngjin Choi Abstract The conformational characteristics of glycosylated- and unglycosylated bovine pancreatic ribonuclease A (RNaseA) were traced with unfolding molecular dynamics simulations using CHARMM program at 470 K. The glycosylated RNase (Glc_RNase) possesses nearly identical protein structure with RNaseA, differing only by presence of a single acetylglucosamine residue N-linked to Asn34 in the RNaseA. Attaching of monomeric N -acetylglucosamine residue to the Asn34 in RNaseA resulted in a change of denaturing process of Glc_RNase. Simulations showed that the unfolding of RNaseA involved significant weakening of nonlocal interactions whereas the glycosylation led Glc_RNase to preserve the nonlocal interactions even in its denatured form. Even in simulations over 8 ns at 470 K, Glc_RNase remained relatively stable as a less denatured conformation. However, conformation of RNaseA was changed to a fully unfolded state before 3 ns of the simulations at 470 K. This difference was due to fact that formation of hydrogen bond bridges and nonlocal contacts induced by the attached N -acetylglucosamine of Glc_RNase showing in the unfolding simulations. These high-temperature unfolding MD simulations provided a theoretical basis for the previous experimental work in which Glc_RNase showed slower unfolding kinetics compared with unglycosylated RNaseA, suggesting that single N-glycosylation induced retardation of unfolding process of the ribonuclease protein. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 114,123, 2008. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] The ribbon of hydrogen bonds and the pseudomolecule in the three-dimensional structure of globular proteins.BIOPOLYMERS, Issue 5 2002Abstract The model of the three-dimensional structure of globular proteins, which is based on a ribbon of hydrogen bonds along the whole of the backbone, is now applied to the comparison between monomeric bovine pancreatic ribonuclease A and dimeric bovine seminal ribonuclease. Some waters are involved in the hydrogen bonding of the ribbon, and the protein molecule plus these waters forms a pseudomolecule. The conformations of the three backbones are essentially identical and the three ribbons of hydrogen bonds are conserved with greater than 90% accuracy. We suggest that the conservation of the backbone conformations of the two molecules is a consequence of the conservation of the ribbons of hydrogen bonds. There are 16 simple mutations between the two molecules, of which 15 involve only side-chain groups with no more than one hydrogen bond to the backbone. Such mutations are not sufficient to change the ribbon of hydrogen bonds and hence there is no change in the backbone conformation. Generalizing this result, we suggest that the conservation of the ribbon is the reason why single point mutations rarely change the conformation of the backbone of the globular proteins. © 2002 Wiley Periodicals, Inc. Biopolymers 65: 347,353, 2002 [source] | ||||||||||