temporary banners

 



 

Journal Issue - Volume 6 Issue 9 (September 1997)

Abstract The general similarity in the forces governing protein folding and protein‐protein associations has led us to examine the similarity in the architectural motifs between the interfaces and the monomers. We have carried out extensive, all‐against‐all structural comparisons between the single‐chain protein structural dataset and the interface dataset, derived both from all protein‐protein complexes in the structural database...

Abstract The crystal structures of the inhibitor domain of Alzheimer's amyloid β‐protein precursor (APPI) complexed to bovine chymotrypsin (C‐APPI) and trypsin (T‐APPI) and basic pancreatic trypsin inhibitor (BPTI) bound to chymotrypsin (C‐BPTI) have been solved and analyzed at 2.1 Å, 1.8 Å, and 2.6 Å resolution, respectively. APPI and BPTI belong to the Kunitz family of inhibitors, which is characterized by a distinctive tertiary...

Abstract Two classes of molecules inhibit the catalytic subunit (C) of the cyclic AMP‐dependent protein kinase (cAPK), the heat‐stable protein kinase inhibitors (PKIs) and the regulatory (R) subunits. Basic sites on C, previously identified as important for R/C interaction in yeast TPKI and corresponding to Lys213, Lys217, and Lys189 in murine Cα, were replaced with either Ala or Thr and characterized for their kinetic properties...

Abstract Mutagenesis studies have revealed that the minimal DNA‐binding domain of the yeast transcription factor ADR1 consists of two Cys2‐His2 zinc fingers plus an additional 20 residues proximal and N‐terminal to the fingers. We have assigned NMR 1'H, 15N, and 13C chemical shifts for the entire minimal DNA‐binding domain of ADR1 both free and bound to specific DNA. 1H chemical shift values suggest little structural difference between the zinc fingers in...

Abstract The electrostatic properties of seven α/β‐barrel enzymes selected from different evolutionary families were studied: triose phosphate isomerase, fructose‐1,6‐bisphosphate aldolase, pyruvate kinase, mandelate racemase, trimethylamine dehydrogenase, glycolate oxidase, and narbonin, a protein without any known enzymatic activity. The backbone of the α/β‐barrel has a distinct electrostatic field pattern, which is dipolar along...

Abstract A peptide comprising the N‐terminal 38 residues of human apolipoprotein C‐I (apoC‐I(1‐38)) was synthesized using solid‐phase methods and its solution conformation studied by CD and 1H NMR spectroscopy. The CD data indicate that apoC‐I(1‐38) has a similar helical content (55%) in the presence of saturating amounts of SDS or egg yolk lysophosphatidylcholine. A structural ensemble of SDS‐bound apoC‐I(1‐38) was calculated from 464 ...

Abstract αtα is a 38‐residue peptide designed to adopt a helical hairpin conformation in solution (Fezoui Y, Weaver DL, Osterhout JJ, 1995, Protein Sci 4286‐295). A previous study of the carboxylate form of αtα by CD and two‐dimensional NMR indicated that the peptide was highly helical and that the helices associated in approximately the intended orientation (Fezoui Y, Weaver DL, Osterhout JJ, 1994, Proc Natl Acad Sci USA...

Abstract Drosomycin is the first antifungal protein characterized recently among the broad family of inducible peptides and proteins produced by insects to respond to bacterial or septic injuries. It is a small protein of 44 amino acid residues extracted from Drosophila melanogaster that exhibits a potent activity against filamentous fungi. Its three‐dimensional structure in aqueous solution was determined using 1H 2D NMR. This...

Abstract Molecular dissection was employed to identify minimal independent folding units in dihydrofolate reductase (DHFR) from Escherichia coli. Eight overlapping fragments of DHFR, spanning the entire sequence and ranging in size from 36 to 123 amino acids, were constructed by chemical cleavage. These fragments were designed to examine the effect of tethering multiple elements of secondary structure on folding and to test if the secondary...

Abstract DsbA, a 21‐kDa protein from Escherichia coli, is a potent oxidizing disulfide catalyst required for disulfide bond formation in secreted proteins. The active site of DsbA is similar to that of mammalian protein disulfide isomerases, and includes a reversible disulfide bond formed from cysteines separated by two residues (Cys30‐Pro31‐His32‐Cys33). Unlike most protein disulfides, the active‐site disulfide of DsbA is highly...

Abstract The surface topology of the Minibody, a small de novo‐designed β‐protein, has been probed by a strategy that combines selective chemical modification with a variety of reagents and mass spectrometric analysis of the modified fragments. Under appropriate conditions, the susceptibility of individual residues primarily depends on their surface accessibility so that their relative reactivities can be correlated with their...

Abstract Electrostatic interactions in a complex of the phospholipase C‐γ, C‐terminal SH2 domain with a high‐affinity binding phosphopeptide representing the sequence around Tyr 1021 of the β platelet‐derived growth factor receptor were studied by pKa determination of various titratable groups over the pH range of 5 to 8. A histidine residue that is highly conserved among SH2 domains (His βD4) and the phosphotyrosine (pTyrj phosphate group show...

Abstract A modification of the Lifson‐Roig formulation of helix/coil transitions is presented; it (1) incorporates end‐capping and coulombic (salt bridges, hydrogen bonding, and side‐chain interactions with charged termini and the helix dipole) effects, (2) helix‐stabilizing hydrophobic clustering, (3) allows for different inherent termination probabilities of individual residues, and (4) differentiates helix elongation in the first...

Abstract Two active site histidine residues have been implicated in the catalysis of phosphatidylinositol‐specific phospholipase C (PI‐PLC). In this report, we present the first study of the pKa values of histidines of a PI‐PLC. All six histidines of Bacillus cereus PI‐PLC were studied by 2D NMR spectroscopy and site‐directed mutagenesis. The protein was selectively labeled with 13Cϵ1‐histidine. A series of 1H‐13C HSQC NMR spectra were acquired over a pH...

Abstract The interactions between calcitonin gene‐related peptide and FAB fragments prepared from two different high‐affinity anti‐CGRP monoclonal antibodies (CB3 and CD1) have been studied at physiological pH using the ability of 1H NMR to detect selectively regions of dynamic flexibility. The 37‐residue peptide retains considerable flexibility in regions of its sequence when bound to both antibodies; in each case, more than half of the...

Page:   1 2 Next