Crystallization of the activated ternary complex of ribulose-1,5-bisphosphate carboxylase-oxygenase isolated from Rhodospirillum rubrum and from an Escherichia coli clone.

Ribulose-1,5-bisphosphate carboxylase-oxygenase was purified from the photosynthetic bacterium Rhodospirillum rubrum as well as from an Escherichia coli clone overproducing the enzyme. Although the latter enzyme contains 25 additional amino acid residues at the N terminus, both preparations yielded isomorphous tetragonal, bipyramidal crystals of the ternary complex of the enzyme with CO2 and Mg2+. Crystallization is sensitive to variation in pH and to the addition of the transition state analog, 2-carboxyarabinitol-1,5-bisphosphate.

Two-dimensional 1H NMR investigation of ribonuclease A and ribonuclease-A--pyrimidine-nucleotide complexes.

Ribonuclease A was studied by two-dimensional 1H NMR spectroscopy. 10 out of 12 alanine and 9 out of 10 threonine spin systems as well as all valine [9], leucine [2] and isoleucine [3] spin systems were identified from the correlated spectroscopy (COSY) and relayed coherence transfer spectroscopy (RCT). Sequence-specific assignments were obtained from nuclear Overhauser effect spectra for proton resonances of 21 amino acid moieties.

Single and twinned crystals of ribulose-1,5-bisphosphate carboxylase-oxygenase from Alcaligenes eutrophus.

Ribulose-1,5-bisphosphate carboxylase-oxygenase (L8S8) from Alcaligenes eutrophus has been crystallized by equilibrium vapor diffusion techniques with ammonium sulfate as precipitant. Crystals thus obtained either as the ternary complex with CO2 and Mg2+ or as the quaternary complex with CO2, Mg2+, and 2-carboxyarabinitol 1,5-bisphosphate, a transition state analogue, diffract at least to 2.8-A resolution.

Cytotoxicity of lectins on rat intestinal mucosa enhanced by neuraminidase.

The lectins wheat germ agglutinin (WGA) and Concanavalin A (ConA) were perfused into an isolated small intestinal segment alone or after prior perfusion with neuraminidase for a 10 day period in the rat. Intestinal morphometry, intraepithelial Lymphocyte (IEL) and round cell content as well as digestive capacity was measured in the loop and in the adjacent segments. Both lectins induce a mucosal transformation in all segments but ConA is more effective than WGA.

1H and 15N NMR investigation of the interaction of pyrimidine nucleotides with ribonuclease A.

Extensive 1H and 15H NMR investigations of the nucleotide moieties capable of hydrogen bonding to ribonuclease A were carried out in order to gain more detailed information on the specificity of nucleotide-enzyme interaction. The 1H investigations focussed on those protons presumed to be involved in hydrogen bonding between the various nucleotides and the enzyme. In particular these were the imino protons of the uridine nucleotides and the amino protons of the cytidine nucleotides.

Consensus structure and evolution of 5S rRNA.

A consensus structure model of 5S rRNA presenting all conserved nucleotides in fixed positions has been deduced from the primary and secondary structure of 71 eubacterial, archaebacterial, eukaryotic cytosolic and organellar molecules. Phylogenetically related groups of molecules are characterized by nucleotide deletions in helices III, IV and V, and by potential base pair interactions in helix IV. The group-specific deletions are correlated with the early branching pattern of a dendrogram calculated from nucleotide substitution data: the first major division separates the group of eubacterial and organellar molecules from a second group containing the common ancestors of archaebacterial and eukaryotic/cytosolic molecules.

Nucleotide sequence of 5S ribosomal RNA from Aspergillus nidulans and Neurospora crassa.

The nucleotide sequences of 5S rRNA molecules isolated from the cytosol and the mitochondria of the ascomycetes A. nidulans and N. crassa were determined by partial chemical cleavage of 3'-terminally labelled RNA.

Physical map of Aspergillus nidulans mitochondrial genes coding for ribosomal RNA: an intervening sequence in the large rRNA cistron.

A detailed map of the 32 kb mitochondrial genome of Aspergillus nidulans has been obtained by locating the cleavage sites for restriction endonucleases Pst I, Bam H I, Hha I, Pvu II, Hpa II and Hae III relative to the previously determined sites for Eco R I, Hind II and Hind III. The genes for the small and large ribosomal subunit RNAs were mapped by gel transfer hybridization of in vitro labelled rRNA to restriction fragments of mitochondrial DNA and its cloned Eco R I fragment E3, and by electron microscopy of RNA/DNA hybrids. The gene for the large rRNA (2.

Split gene for mitochondrial 24S ribosomal RNA of Neurospora crassa.

The 60 kb circular mitochondrial genome of N. crassa has previously been shown to contain a single transcription unit for 17S and 24S rRNA mapping within the largest Eco RI fragment E1 (19.6 kb).

Age-related changes in the proteolytic enzymes of mammalian lens.

A longitudinal study has been conducted on three exopeptidases which include an esterase, leucine aminopeptidase, and a triglycinopeptidase and two endopeptidases, a neutral protease and a proteinase or catheptic activity in bovine lenses. The esterase and leucine aminopeptidase behave similarily showing increased activities with aging. Triglycinopeptidase has a somewhat lower order of magnitude when compared to the other exopeptidases.