Cestodes of birds from the Ivory Coast. Species of the genus Anonchotaenia Cohn, 1990

Five taxa included in the cestode genus Anonchotaenia (Cyclophyllidea, Paruterinidae) have been found in various birds from the Ivory Coast (West Africa). The hosts belong to the families Hirundinidae and Corvidae. A. (Paranonchotaenia) prionopos n. sp., parasitic in Prionops plumata, and A. (P.) malaconoti n. sp, parasitic in Malaconotus blanchoti, are placed in a new subgenus named Paranonchotaenia, which is erected for the Anonchotaenia species showing genital ducts passing between the longitudinal excretory stems. A. (P.) prionopos is characterised by a rather short cirrus-pouch, six to seven testes, and an integumental cavity at the distal extremity of the cirrus-pouch in gravid proglottides. A. (P.) malaconoti differs from the former species mainly by the larger cirrus-pouch and a slightly greater number of testes. The other three species are A. longiovata, parasitic in Hirundo semirufa; A. globata, parasitic in Psadiloprocne obscura (the latter two species are recorded from new hosts and new geographical areas); and Anonchotaenia sp., parasitic in Hirundo rustica. It is assumed that the subgenus A. (Anonchotaenia) is rather a parasite of the Passerida and that the subgenus A. (Paranonchotaenia) tends to be parasitic in the Corvida.This paper is a part of the author's thesis.This paper is a part of the author's thesis.     

Improvement of four sigma analysis for the investigation of oxygen evolution by Photosystem II

We present here an improvement to the analysis of oxygen evolution with four sigma coefficients (4-S) by computing z, the sum of the S-state probabilities, which was introduced earlier (Delrieu and Rosengard 1987, Biochim Biophys Acta 892: 163–171). We demonstrate that z is equal to the ratio of two consecutive Mean Y (the estimation of the steady state oxygen production based on local properties) found by three sigma analysis. The quantity z is useful for computing double-hits, and for showing the inactivation/activation processes of PS II complexes. Three sigma analysis assumes z=1 exactly; since this is not verified, it is argued that four sigma analysis is closer to the real workings of the water oxidizing complex. Oxygen evolution can then be interpreted in the frame of a modified Kok's model where the sum of the probabilities equals z. We therefore suggest that the closer fitting of four sigma analysis to oxygen production data is not simply due to an extra, unnecessary variable, but to the fact that PS II complexes can be inactivated and reactivated under flashing light. Finally, in order to facilitate the use of four sigma analysis, a computer program is made available upon request.     

Immunochemical characterisation of parathyroid hormone-related protein from tumor and non-tumor cells

The molecular forms of parathyroid hormone-related protein (PTHRP) in conditioned media from the BEN human lung cancer cell line, rat parathyroid cells (PT-r) and human keratinocytes were studied by gel-filtraton chromatography with assay of PTHRP by immunoassays and bioassay. Immunoreactivity (1–86 and 1–34) and bioactivity (1–34) in conditioned media eluted as a coincident major peak (approx. molecular mass 19–22 kDa) and there was evidence of amino-terminal species in the molecular mass range 10–16 kDa in BEN and keratinocyte media. Western blotting of PTHRP affinity purified by monoclonal antibodies directed at regions 1–34 or 37–67, identified a major species in all cell cytosols and media with an apparent molecular mass of 24–25 kDa, consistently slighty larger than recombinant PTHRP(1–141) (mobility of 21 kDa) which may represent an intact or native form of PTHRP. Additional amino-terminal species were identified in medium from keratinocytes (16 and 7 kDa), BEN cells (18 and 14 kDa) and PT-R cells (17 kDa), suggesting that processing occurs at the C-terminus and within the mid-region to form a range of amino-terminal fragments.     

Computation of relaxation matrix elements from incomplete NOESY data sets

Summary The structural determination of biological molecules in solution by NMR relies on the determination of a set of interatomic distances obtained by measurement of intramolecular nuclear Overhauser effects (NOE). It is shown in this paper that it is possible to obtain the accurate relaxation rate (and hence the interatomic distance) from the direct measurement of a single NOE signal. The precise analysis of a NOESY peak evolution with respect to the mixing time allows the evaluation of the relaxation parameters for the pair of spins under consideration. This is done without any assumption on the relaxation of unmeasured spins, or on the movement of the molecule. The theoretical basis of this method is presented. In order to evaluate the proposed method, a simulated case on the protein BPTI is studied, which shows that the method performs very well even in the case of noisy data sets.     

Changes in soil microflora associated with control of Sclerotium Rolfsii by Furfuraldehyde

The efficacy of 2‐furfuraldehyde for control of Sclerotium rolfsii was studied in laboratory and greenhouse experiments. Mycelial growth of the fungus was reduced proportionally with concentrations of 0.1–0.5 ml furfuraldehyde l^‐1 agar medium, and viability of sclerotia diminished on exposure to 2‐furfuraldehyde vapours. Detectable populations of bacteria and fungi, including Trichoderma spp., were reduced significantly (9=0.05) when furfuraldehyde was added to the agar used for soil dilution plates of untreated soil. Repeated treatments of natural soil with the fumigant significantly increased populations of Trichoderma spp. and bacteria, but diminished numbers of actinomycetes. Increasing dosages applied to soil artificially infested with S. rolfsii caused a reduction of disease on lentil, Lens culinaris. Results indicate that the compound, when applied to field soil, changes the composition of soil microflora and has potential for integrated control of S. rolfsii.     

Novel heme-binding component in the serum of the channel catfish (Ictalurus punctatus)

The serum of the channel catfish (Ictalurus punctatus) was examined for heme- and hemoglobin-binding proteins. Electrophoretic mobility retardation assays failed to detect a hemoglobin-binding material similar to mammalian haptoglobin; however, a heme-binding component (not previously described) was identified in catfish seru. The heme-binding component was purified by gel filtration chromatography; electrophoretic analyses suggested it to be composed of two polypeptide subunits of molecular masses about 115 and 98 kDa. This composition is inconsistent with hemopexin, the known heme-binding serum protein of mammals. Although it was not fully saturated with heme, the catfish component contained detectable heme in normal sera. When complexed by the binding material, heme was used as an iron source by isolates of the bacterial Gram-negative genusAeromonas; the capacity of other bacteria to use the complex was not tested. The physiological function of the catfish heme-binding serum protein is presently not clear.     

Evidence for pyroglutamyl peptidase I and prolyl endopeptidase activities in the rat insulinoma cell line RINm 5F: lack of relationship with TRH metabolism

Thyrotropin-R eleasing hormone (TRH)-degrading pyroglutamyl peptidase I(PGP I) and prolyl endopeptidase (PE) activities have been demonstrated in rat insulinoma RINm 5F cell line. These two enzymes catalyze the conversion of TRH to Histydyl-Proline-Diketopiperazine and to acid TRH respectively.After cell fractionation, we found all the PGP I and PE activities in the cytosolic fraction. The membranebound PGP II activity is not detectable in the RINm 5F cells. Further investigations on these two cytosolic enzymes show that pyroglutamyl- and proline-containing peptides are inhibitors of each TRH-degrading enzyme.Gelfiltration chromatography on Sephadex G100 shows that PGP I and PE activity have an apparent molecular mass of about 18 kDa and 57 kDa, respectively. Kinetic analysis with TRH as substrate, gives a Km of 44 µM and 235 µM, and a Vmax of 1.49 and 8.80 pmoUmin/µg protein for PGP I and PE, respectively. Immunoreactive TRH, His-Pro-Diketopiperazine and acid TRH levels in the cell line extracts are 2.2 ± 0.9, 22.5 ± 11.1 and 28.7 ± 14.6pg/10⁶ cells, respectively. When cells have been incubated for 2 to 72 hours with a P. E. inhibitor (Z-Gly-Pro-CHN₂) at 5 × 10^–7M, both cell PGP I and PE activities are inhibited. No change in the cellular content of immunoreactive TRH, His-Pro-Diketopiperazine and acid TRH have been observed in treated cells.These data suggest that TRH is not degraded by cytosolic, unspecific PGP I and PE enzymes in RINm 5F. The finding that these cells contain 10 and 13 times more His-Pro-Diketopiperazine and acid TRH than TRH may be an indirect evidence for the existence of another precursor than TRH for these two peptides or of the possibility that TRH can be degraded by other peptidases.Abbreviations TRH Thyrotropin-Releasing Hormone or Thyroliberin - His-Pro-DKP Histidyl-ProlineDiketopiperazine - TRH-OH acid TRH or deamidated TRH - LH-RH Luteinizing Hormone-Releasing Hormone - Z-Gly-Pro-CHN₂ N-benzyloxycarboxyl-Gly-Pro-diazomethylketone - PGP Pyroglutamyl Peptidase, PGP I (EC 3.4.19.3) and PGP II (EC 3.4.19.-) - PE Prolyl Endopeptidase or post-proline cleaving enzyme (EC 3.4.21.26)     

Osteogenesis imperfecta due to recurrent point mutations at CpG dinucleotides in the COL1A1 gene of type I collagen

Summary Most individuals with osteogenesis imperfecta (OI) are heterozygous for dominant mutations in one of the genes that encode the chains of type I collagen. Each of the more than 30 mutations characterized to date has been unique to the affected member (s) of the family. We have determined that two individuals with a progressive deforming variety of OI, OI type III, have the same new dominant mutation [1(I)gly154 to arg] and that two unrelated infants with perinatal lethal OI, OI type II, share a second new dominant muation [1(I)gly1003 to ser]. These mutations occurred at CpG dinucleotides, in a manner consistent with deamination of a methylated cytosine residue, and raise the possibility that CpG dinucleotides are common sites of recurrent mutations in collagen genes. Further, these findings confirm that the OI type-III phenotype, previously thought to be inherited in an autosomal recessive manner, can result from new dominant mutations in the COL1A1 gene of type-I collagen.     

Protein phosphorylation in the facultative chemolithotrophThiobacillus novellus

The phosphorylation of at least five proteins with M_r of about 160,000; 93,000; 85,000; 45,000; and 29,000 respectively was demonstrated in crude extracts from the facultative chemolithotrophThiobacillus novellus. The incorporation of [-³²P]phosphate from ATP into these proteins was dependent on the presence of magnesium ion. The phosphorylation reactions were found to be reversible and required 12.5 mM NaF for maximal activity, indicating the action of phosphatases. In addition, 3,5-cAMP had little effect on protein kinase activity, whereas Ca²⁺ alone was weakly stimulatory. This activation was enhanced by the addition of 3,5-cAMP. Ca²⁺ with calmodulin had a strong stimulatory effect on phosphate incorporation into the proteins. A highly purified preparation containing only the 160, 93, and 85 kDa proteins phosphorylated histone, whereas the uptake of³²P by the three proteins was inhibited. Rabbit muscle phosphorylase b prevented incorporation of radiolabel only into the 160 and 93 kDa proteins.