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Journal Issue - Volume 1 Issue 10 (October 1992)

  • Recalling the past

  • Hans Neurath
  • Published in Wiley Interscience on Dec 31, 2008
  • DOI: 10.1002/pro.5560011001 (p 1235-1235)

Abstract Retroviral proteases are obligate homodimers and play an essential role in the viral life cycle. Dissociation of dimers or prevention of their assembly may inactivate these enzymes and prevent viral maturation. A salient structural feature of these enzymes is an extended interface composed of interdigitating N‐ and C‐terminal residues of both monomers, which form a four‐stranded β‐sheet. Peptides mimicking one β‐strand...

Abstract Macromolecular crystal growth experiments, using satellite tobacco mosaic virus (STMV) and canavalin from jack beans as samples, were conducted on a US Space Shuttle mission designated International Microgravity Laboratory — 1 (IML‐1), flown January 22–29, 1992. Parallel experiments using identical samples were carried out in both a vapor diffusion‐based device (PCG) and a liquid‐liquid diffusion‐based instrument...

Abstract Proteins present unique folding structures whose conformations are determined primarily by their amino acid sequences. At present, there is no algorithm that would correlate the sequences with the structures determined by X‐ray analysis or NMR. Comparative modeling of a new protein sequence based on the known structure of a functionally related protein promises to yield model structures that may provide relevant properties...

Abstract A method of optimally superimposing n coordinate sets on each other by rigid body transformations, which minimizes the sum of all n(n ‐ 1)/2 pairwise residuals, is presented. In the solution phase the work load is approximately linear on n, is independent of the size of the structures, is independent of their initial orientations, and terminates in one cycle if n = 2 or if the coordinate sets are exactly superposable, and otherwise takes a number...

Abstract Analysis of tomato pectinesterase by carboxymethylation, with and without reduction, shows that the enzyme has two intrachain disulfide bridges. Analysis of fragments obtained from the native enzyme after digestion with pepsin identified bridges connecting Cys‐98 with Cys‐125, and Cys‐166 with Cys‐200. The locations of disulfide bridges in tomato pectinesterase are not identical to those in three distantly related...

Abstract The specificities of 15 cellulolytic enzymes have been examined using chromophoric glycosides derived from d‐glucose, cellobiose, higher cellooligosaccharides, lactose, d‐xylose, and β‐(1,4)‐xylobiose. Coinciding with a classification based on hydrophobic cluster analysis of amino acid sequences, six families each showing a characteristic specificity pattern were observed. Furthermore, in these cases where the anomeric...

Abstract Thiourea dioxide was used in chemical modification studies to identify functionally important amino acids in Escherichia coli CTP synthetase. Incubations at pH 8.0 in the absence of substrates led to rapid, time dependent, and irreversible inactivation of the enzyme. The second‐ order rate constant for inactivation was 0.18 M−1 s−1. Inactivation also occurred in the absence of oxygen and in the presence of catalase, thereby ruling out...

Abstract The C‐terminal region of Pseudomonas aeruginosa strain K (PAK) pilin comprises both an epitope for the strain‐specific monoclonal antibody PK99H, which blocks pilus‐mediated adherence, and the adherence binding domain for buccal and tracheal epithelial cells. The PK99H epitope was located in sequence 134–140 (Asp‐Glu‐Gln‐Phe‐Ile‐Pro‐Lys) by using a single alanine replacement analysis on the 17‐residue synthetic peptide corresponding ...

Abstract The thermal unfolding of the coiled‐coil α‐helix of recombinant αα‐tropomyosin from rat striated muscle containing an additional 80‐residue peptide of influenza virus NS1 protein at the N‐terminus (fusion‐tropomyosin) was studied with circular dichroism and fluorescence techniques. Fusion‐tropomyosin unfolded in four cooperative transitions: (1) a pretransition starting at 35 °C involving the middle of the molecule; (2) a major...

Abstract Sequence comparison studies revealed that the drug resistance transporter of Streptomyces peucetius (DrrAB) and two nodulation gene products (NodIJ) of Rhizobium leguminosarum are homologous to proteins encoded by three sets of genes that comprise capsular polysaccharide export systems in gram‐negative bacteria: KpsTM of Escherichia coli, BexABC of Haemophilus influenzae, and CtrDCB of Neisseria meningitidis. These five systems comprise a new...

Abstract Local determinants of 310‐helix stabilization have been ascertained from the analysis of the crystal structure data base. We have clustered all 5‐length substructures from 51 nonhomologous proteins into classes based on the conformational similarity of their backbone dihedral angles. Several clusters, derived from 310‐helices and multiple‐turn conformations, had strong amino acid sequence patterns not evident among α‐helices. Aspartate...

Abstract The cellular prion protein (PrPC) is encoded by a chromosomal gene, and its scrapie isoform (PrPSc) features in all aspects of the prion diseases. Prior to the studies reported here, purification of PrPC has only been accomplished using immunoaffinity chromatography yielding small amounts of protein. Brain homogenates contain two PrPC forms designated PrPC‐I and ‐II. These proteins were purified from a microsomal fraction by detergent extraction...

Abstract An autophosphorylation site in the activated insulin receptor tyrosine kinase domain has three tyrosines phosphorylated when fully activated. To begin to examine recognition of triphosphotyrosyl sites by protein tyrosine phosphatases in possible control of signal transduction a triphosphotyrosyl dodecapeptide TRDIpYETDpYpYRK corresponding to residues 1,142–1,153 of the insulin receptor was prepared and incubated with the...

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