Properties of glutamate dehydrogenase from Beta vulgaris

Glutamate-NAD oxidoreductase, E.C. 1.4.1.3 (GDH), from seedlings of Beta vulgaris cv. Rota, Jahnsch Peragis Comp., was enzymatically characterized. This enzyme with molecular weight of 2.6 × 10⁵ has a pH optimum of around 8 for animation of α-KGA and around 9.5 for the desamination of glutamate. The apparent K_m for α-KGA is 6.7 × 10^?4M, for NH₃ 2.5 × 10^?3M, for NADH 3.2 × 10^?5M and for NAADPH 5.5 × 10^?4M. NAD¹ inhibits the reaction non-competitively when NADPH serves as substrate. The apparent K¹ is 4.5 × 10^?4M. The data are discussed on relation to the properties of GDH from other plant sources.     

Identification of three adjacent amino acids of interleukin-2 receptor beta chain which control the affinity and the specificity of the interaction with interleukin-2.

The beta chain of the interleukin-2 (IL-2) receptor (IL-2R beta) and the interleukin-3 (IL-3) binding protein AIC2A are members of the family of cytokine receptors, which also includes the receptors for growth hormone (GHR) and prolactin. A four amino acid sequence of AIC2A has recently been shown to be critical for IL-3 binding. We analyze here the function of the analogous sequence of human IL-2R beta and identify three amino acids, Ser132, His133 and Tyr134, which play a critical role in IL-2 binding. We show that some mutant IL-2 proteins with substitutions of a critical Asp residue in the N-terminal alpha-helix bind the mutant IL-2R beta receptor with a higher affinity than the wild-type receptor. This suggests that the critical Asp34 in the ligand and the sequence Ser-His-Tyr (positions 132-134) in the receptor interact directly. On the double barrel beta-stranded structural model of cytokine receptors, the residues important for ligand binding in IL-2R beta, AIC2A and GHR map to strikingly similar locations within a barrel, with the interesting difference that it is the N-terminal barrel for GHR and the C-terminal barrel for IL-2R beta and AIC2A.     

Relationships within the Melitaea phoebe species group (Lepidoptera: Nymphalidae): new insights from molecular and morphometric information

The genus Melitaea consists of about 80 species, divided into ten species groups, which are all restricted to the Palaearctic region. The Melitaea phoebe group was defined by Higgins based on morphological characters such as wing pattern and genital structures. According to his interpretation, the M. phoebe group included seven species: M. phoebe, M. sibina, M. scotosia, M. aetherie, M. collina, M. consulis and M. turkmanica. The taxonomy of the phoebe species group has been poorly resolved and recent results on the species composition within the group suggest the need for a re‐evaluation. In this study molecular sequences (5985 bp) including one mitochondrial (COI) and up to six nuclear (CAD, EF‐1α, GAPDH, MDH, RpS5 and wingless) gene regions from 38 specimens of the Melitaea phoebe species group sensu Higgins and some closely related taxa from the Palaearctic region were analysed. The possible evolution of the processus posterior of the male genitalia was also reconstructed based on a shape mapping technique. The analysis of the combined data shows a very clear pattern and almost all relationships are highly supported. Based on the combined Bayesian tree and the shape of the processus posterior of the male genitalia, four main groups are recognised: (i) collina group, (ii) arduinna group, (iii) aetherie group and (iv) phoebe group. The status of M. ornata, M. zagrosi and M. scotosia as species is confirmed, and the results also indicate that M. telona (s.s.) from Israel is a separate species.     

The prevalence of clinically diagnosed ankylosing spondylitis and its clinical manifestations: a nationwide register study

IntroductionPrevalence estimates of ankylosing spondylitis vary considerably, and there are few nationwide estimates. The present study aimed to describe the national prevalence of clinically diagnosed ankylosing spondylitis in Sweden, stratified according to age, sex, geographical, and socio-economic factors, and according to subgroups with ankylosing spondylitis-related clinical manifestations and pharmacological treatment.MethodsAll individuals diagnosed with ankylosing spondylitis according to the World Health Organization International Classification of Disease codes, between 1967 and 2009, were identified from the National Patient Register. Data regarding disease manifestations, patient demographics, level of education, pharmacological treatment, and geographical region were retrieved from the National Patient Register and other national registers.ResultsA total of 11,030 cases with an ankylosing spondylitis diagnosis (alive, living in Sweden, and 16 to 64 years old in December 2009) were identified in the National Patient Register, giving a point prevalence of 0.18% in 2009. The prevalence was higher in northern Sweden, and lower in those with a higher level of education. Men had a higher prevalence of ankylosing spondylitis (0.23% versus 0.14%, P < 0.001), a higher frequency of anterior uveitis (25.5% versus 20.0%, P < 0.001) and were more likely to receive tumor necrosis factor inhibitors than women (15.6% versus 11.8% in 2009, P < 0.001). Women were more likely than men to have peripheral arthritis (21.7% versus 15.3%, P < 0.001), psoriasis (8.0% versus 6.9%, P = 0.03), and treatment with oral corticosteroids (14.0% versus 10.4% in 2009, P < 0.001).ConclusionThis nationwide, register-based study demonstrated a prevalence of clinically diagnosed ankylosing spondylitis of 0.18%. It revealed phenotypical and treatment differences between the sexes, as well as geographical and socio-economic differences in disease prevalence.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0627-0) contains supplementary material, which is available to authorized users.     

A new species of Heth Cobb, 1898 (Nematoda: Rhigonematida: Hethidae) from an Australian millipede (Myriapoda: Diplopoda: Spirostreptida)

Abstract

A new species of nematode, Heth baudini sp. n. from a diplopod (Spirostreptida: Iulomorphidae Verhoeff, 1924) collected in Queensland, Australia, is described and illustrated. The cephalic and cervical cuticular ornamentation of females of H. baudini sp. n. is similar to those of South-East Asian and Australasian Heth species. Heth baudini sp. n. females are particularly close to Heth taynguyeni from Vietnam but can be distinguished by the shape of the lateral lappets, which in H. taynguyeni limit the trapezium-shaped region of smooth cuticle unlike the elliptical region in H. baudini sp. n., and by the presence of lateral spines only half the size. The cuticle of the H. baudini sp. n. is finely annulated along the entire body, whereas H. taynguyeni has broader rings behind the first pair of lateral spines, each consisting of five or six narrower rings separated from each other by deeper furrows. Males of H. baudini sp. n. are characterised by the presence of a bursa-like fold on the tail and can be distinguished from other species of the genus by the presence of somatic papillae embedded into the bursal fold.     

Identification of key residues in the amino-terminal third of human interleukin-1 alpha

Two mutational approaches were used to perform a thorough structure-function analysis of the first 53 residues of the 159-residue cytokine human interleukin-1 alpha (hIL-1 alpha). In this study, a total of 26 deletions, 97 multiple amino acid substitutions, and 46 single amino acid substitutions were examined. A synthetic hIL-1 alpha gene with many unique restriction sites was constructed to facilitate the molecular manipulations that were performed. The mutational methods employed include: Bal-31 exonuclease-generated deletions at unique restriction sites and combinatorial cassette mutagenesis via segment replacement with synthetic DNA. The mutant hIL-1 alpha proteins were expressed at high levels in Escherichia coli and were assayed for biological activity in a mouse T cell proliferation assay. We observed that the activity of hIL-1 alpha was extraordinarily sensitive to deletion mutations. Most internal deletions of as few as 1 or 2 residues substantially reduced biological activity. Combinatorial cassette mutagenesis on residues 13-53 of hIL-1 alpha identified 15 important residue positions. Of these, 8 displayed strong preferences for residues with hydrophilic side chains, and the remainder preferred hydrophobic side chains. We found that functional hIL-1 alpha had an absolute requirement for a basic residue (Arg, Lys, or His) at either position 15 or 16, and that Leu was preferred at position 40.     

Antibodies of restricted heterogeneity directed against the cardiac glycoside digoxin.

Intravenous injection of New Zealand White rabbits with type III pneumococcal polysaccharide vaccine conjugated with the cardiac glycoside digoxin resulted in the production of both antidigoxin and anti-type III pneumococcal polysacharide antibodies. Among antisera of 12 rabbits examined during their peak antibody production periods, 1 to 20 mg (mean, 5.4 mg) of antidigoxin antibody could be recovered from 1 ml of serum. Antisera from five of these 12 rabbits contained antidigoxin antibodies of restricted heterogeneity as demonstrated by urea-polyacrylamide disc gel electrophoresis of fully reduced and alkylated antibodies. From the antisera of four of these five rabbits, electrophoretically homogeneous antibodies (1 to 5 mg/ml antiserum) could be isolated by affinity chromatography on ouabain-amine-Sepharose columns. The structural homogeneity of two of these antidigoxin antibodies was confirmed by amino acid sequence analysis of purified light chains through the first hypervariable region. These data suggest that the conjugation of small molecules to bacterial polysaccharide vaccines may provide a general method for synthesis of immunogens that can regularly elicit antihapten antibodies of restricted heterogeneity.