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Journal Issue - Volume 4 Issue 3 (March 1995)

Abstract Structure‐based mutational analysis of serine protease specificity has produced a large database of information useful in addressing biological function and in establishing a basis for targeted design efforts. Critical issues examined include the function of water molecules in providing strength and specificity of binding, the extent to which binding subsites are interdependent, and the roles of polypeptide chain...

Abstract Glycosidases play a key role in a number of biological processes and, as such, are of considerable clinical and bio‐technological importance. Knowledge of the identities of catalytically important active site residues is essential for understanding the catalytic mechanism, for enzyme classification, and for targeted bioengineering of glycosidases with altered characteristics. Here we review and discuss traditional...

Abstract Zinc endopeptidase thermolysin can be inhibited by a series of phosphorus‐containing peptide analogues, Cbz‐Gly‐ψ(PO2)‐X‐Leu‐Y‐R (ZGP(X)L(Y)R), where X = NH, O, or CH2; Y = NH or O; and R = Leu, Ala, Gly, Phe, H, or CH3. The affinity correlation as well as an X‐ray crystallography study suggest that these inhibitors bind to thermolysin in an identical mode. In this work, we calculate the electrostatic binding free energies for a series of 13...

Abstract The mode of binding of interleukin‐4 (IL‐4) to its two known receptors, specific receptor IL‐4R and a shared receptor γc, was investigated using gel filtration and gel electrophoresis. A ternary complex between IL‐4 and the soluble domains of the two receptors was shown to exist in solution. The association constant between γc and the stable complex of IL‐4/sIL‐4R is in the millimolar range, making the ternary complex a feasible target for...

Abstract Experimental studies on a bacterial sulfate receptor have indicated anomalous relative binding affinities for the mutations Ser130 → Cys, Ser130 → Gly, and Ser130 → Ala. The loss of affinity for sulfate in the former mutation was previously attributed to a greater steric effect on the part of the Cys side chain relative to the Ser side chain, whereas the relatively small loss of binding affinity for the latter two mutations...

Abstract Simultaneous sequencing, using a combination of mass spectrometry and Edman degradation, of three approximately 15‐kDa variants of a cuticular protein extracted from the meal beetle Tenebrio molitor larva is demonstrated. The information obtained by matrix‐assisted laser desorption ionization mass spectrometry (MALDI MS) time‐course monitoring of enzymatic digests was found essential to identify the differences among the three variants...

Abstract The high‐affinity interaction between protein kinase inhibitor (PKI)(6–22)amide (Thr6‐Tyr‐Ala‐Asp‐Phe‐Ile‐Ala‐Ser‐Gly‐Arg‐Thr‐Gly‐Arg‐Arg‐Asn‐Ala‐Ile22‐NH2) and the catalytic subunit of cAMP‐dependent protein kinase requires both the N‐terminal Thr6 to Ile11 sequence of the inhibitor peptide and its C‐terminal pseudosubstrate site comprised of Arg15 to Ile22. Small angle X‐ray scattering data indicate that PKI(6–22)amide has a compact, rather than extended,...

Abstract The stability of ribonuclease T2 (RNase T2) from Aspergillus oryzae against guanidine hydrochloride and heat was studied by using CD and fluorescence. RNase T2 unfolded and refolded reversibly concomitant with activity, but the unfolding and refolding rates were very slow (order of hours). The free energy change for unfolding of RNase T2 in water was estimated to be 5.3 kcal‐mol−1 at 25 °C by linear extrapolation method. From the...

Abstract The primary structural features that render human monoclonal light chains amyloidogenic are presently unknown. To gain further insight into the physical and biochemical factors that result in the pathologic deposition of these proteins as amyloid fibrils, we have selected for detailed study three closely homologous protein products of the light‐chain variable‐region single‐gene family VkIV. Two of these proteins, REC and...

Abstract Two isoforms of the heterodimeric enzyme penicillin G acylase (EC 3.5.1.11) from Providencia rettgeri ATCC 31052 (strain Brol) were purified to near homogeneity. The isoforms exhibited comparable enzymatic activities but differed slightly in the molecular weight and pI of their respective α‐subunit. The origin of this difference was traced to the partial conversion of the N‐terminal Gln of the α‐subunit to pyrrolidonecarboxylic acid (pyro‐Glu)....

Abstract The three‐dimensional structures of native partridge egg‐white lysozyme (PEWL) and PEWL complexed with tri‐N‐acetylchitotriose inhibitor have been determined crystallographically and refined at 1.9 Å resolution. Crystals of native and complexed protein are isomorphous and have space group and cell dimensions that are identical to those of hen egg‐white lysozyme (HEWL) under similar crystallization conditions. Full occupancy of the...

  • Refined solution structure of human profilin I

  • William J. Metzler, Bennett T. Farmer, Keith L. Constantine, Mark S. Friedrichs, Luciano Mueller, Thomas Lavoie
  • Published in Wiley Interscience on Dec 24, 2008
  • DOI: 10.1002/pro.5560040312 (p 450-459)

Abstract Profilin is a ubiquitous eukaryotic protein that binds to both cytosolic actin and the phospholipid phospha‐tidylinositol‐4,5‐bisphosphate. These dual competitive binding capabilities of profilin suggest that profilin serves as a link between the phosphatidyl inositol cycle and actin polymerization, and thus profilin may be an essential component in the signaling pathway leading to cytoskeletal rearrangement. ...

Abstract Type II antifreeze proteins (AFP), which inhibit the growth of seed ice crystals in the blood of certain fishes (sea raven, herring, and smelt), are the largest known fish AFPs and the only class for which detailed structural information is not yet available. However, a sequence homology has been recognized between these proteins and the carbohydrate recognition domain of C‐type lectins. The structure of this domain from...

Abstract Fasciclin III is an integral membrane protein expressed on a subset of axons in the developing Drosophila nervous system. It consists of an intracellular domain, a transmembrane region, and an extracellular region composed of three domains, each predicted to form an immunoglobulin‐like fold. The most N‐terminal of these domains is expected to be important in mediating cell‐cell recognition events during nervous system development. To...

Abstract Staphylococcal nuclease is found in two folded conformations that differ in the isomerization of the Lys 116‐ Pro 117 peptide bond, resulting in two different conformations of the residue 112–117 loop. The cis form is favored over the trans with an occupancy of 90%. Previous mutagenesis studies have shown that when Lys 116 is replaced by glycine, a trans conformation is stabilized relative to the cis conformation by the release of steric strain in...

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