Conservation of Amino Acid Sequences Between Human and Porcine Choline Acetyltransferase

Abstract: The amino acid sequence of 11 peptides generated from human placental choline acetyltransferase was compared to the corresponding amino acid sequences predicted from the nucleotide sequence of a recently cloned porcine choline acetyltransferase cDNA. These peptides, which were generated by cyanogen bromide cleavage or tryptic digestion, accounted for 23% of the amino acids in the enzyme. Of the 145 amino acids sequenced eight differed between the two species, yielding an identity of 94% over the regions sampled.
Of the eight amino acids that differed six could represent single base changes in the DNA sequence. These findings demonstrate strong sequence similarity between porcine and human choline acetyltransferase and indicate that they are closely related evolutionarily.     

Group II phospholipase A2 inhibitors suppressed lysophosphatidylserine-dependent degranulation of rat peritoneal mast cells.

Rat peritoneal mast cells were sensitized with IgE and challenged with the specific antigen in the presence of lysophosphatidylserine (lysoPS), an essential co-factor for rodent connective tissue mast cell degranulation, and the effects of phospholipase A2 inhibitors were examined. Mepacrine, a known inhibitor of phospholipase A2, at concentrations below 10(-5) M and anti-rat 14-kDa group II phospholipase A2 antibody inhibited histamine release, while they did not affect the prostaglandin generation. Like histamine release, prostaglandin generation in IgE- and antigen- challenged rat peritoneal mast cells was dependent on the presence of lysoPS. These results indicate that 14-kDa group II phospholipase A2 may play an essential role in IgE-, antigen-, and lysoPS-dependent degranulation process of rat peritoneal mast cells and that the mechanism whereby it participates may not be due to the production of lysoPS from PS in mast cell membranes.     

Steady-state kinetics of autoxidation of NAD(P)H initiated by hydroperoxyl radical, the acid form of superoxide anion radical.

Rates of autoxidation of NAD(P)H initiated by hydroperoxyl radical, the acid form of superoxide anion radical which was generated by xanthine/xanthine oxidase, followed a typical autoxidation kinetic equation. Second-order rate constants for the reactions of NADPH and NADH with hydroperoxyl radical were found to be 9.82 +/- 0.13 x 10(4) M-1s-1 and 9.26 +/- 0.58 x 10(4) M-1s-1 at 25 degrees C, respectively. Rates of the reactions between NAD(P)H and superoxide to give degraded products other than NAD(P)+ were also investigated.     

Organomercurial resistance determinants in Pseudomonas K-62 are present on two plasmids

Pseudomonas strain K-62 was found to contain six plasmids. A mutant derivative cured of the 26-kb plasmid showed a higher sensitivity to mercurials; however, the strain was still able to volatilize them. Loss of the 68-kb plasmid.in addition to the 26-kb plasmid abolished the ability of mercury volatilization in this strain and led to a further decrease in the level of mercurial resistance. These results are the first to demonstrate that the organomercurial resistance of Pseudomonas strain K-62 is plasmid-based, and that both the 26- and 68-kb plasmids are required for full expression of the mercurial resistance. Probes specific for the mer genes merA, merB, and merR strongly hybridized with the 26-kb plasmid, but not with the 68-kb plasmid. Two fragments of the 26-kb plasmid that hybridized with the mer genes were cloned and expressed in Escherichia coli. One recombinant plasmid (pMRA17) inducibly encoded a typical broad-spectrum mercurial resistance, whereas the other recombinant plasmid (pMRB01) constitutively conferred hypersensitivity to phenylmercury in the absence of mercuric reductase activity. The results suggest that the two organomercurial lyases in the cells are transcribed from different operator-promoters.     

Effect of radiation quality on growth, nitrogen uptake, and HCO3-, CO2 and pH interactions in Ulva pertusa

A floating sterile mutant of Ulva pertusa, which grows faster than the wild type and also during summer periods, was grown in the laboratory under "white light" (WR as reference), broad band isoquantic red (600 - 700 nm, RR) and blue (400 - 500 nm, BR) radiation. The observed specific growth rates at WR, BR, and RR were 8.6, 2.15, and 1.2 %, respectively. A stimulatory effect of BR on the growth at low irradiance (60 μmol m-2 s-1) was observed during the 15 d of culture. Around 42.1 % of total nitrogen was used by Ulva mutant in WR, but under BR and RR it was around 27.0 and 16.7 %, respectively. However, the utilization of nitrogen under BR was significantly higher than under RR. Considerable CO2 fluctuation in the light and dark periods was observed in all the cultures, and it was higher under WR, followed by BR and RR. The possible growth promoting effect of BR includes nitrogen uptake and the consumption of HCO3- which in turn leads to reduced air CO2 concentration in the medium. This revised version was published online in August 2006 with corrections to the Cover Date.     

Characterization of platelet abnormalities of Tester Moriyama (TM) rats with storage pool deficiency

Platelet abnormalities of Tester Moriyama (TM) rats, which have prolonged bleeding time with normal platelet count, were characterized by comparison with those of fawn-hooded (FH) rats with platelet storage pool deficiency (SPD). Morphologically, the dense granules were virtually lacking in platelets from TM and FH rats. Platelets from TM and FH rats aggregated in response to adenosine diphosphate (ADP), but failed to have secondary aggregation. In contrast, platelet aggregation was completely absent in response to 1 to 20 micrograms of collagen/ml, although partial aggregation was observed at the higher dosage of 50 micrograms/ml. Normal amounts of platelet membrane glycoproteins IIb/IIIa were expressed in TM and FH rats, but platelet adenosine triphosphate (ATP) and ADP contents were lower than those in platelets from control Wistar rats. Platelet ATP-to-ADP ratio of TM and FH rats was significantly higher than that of Wistar rats. Serotonin content in platelets from TM and FH rats was 20 to 25% that of Wistar rat platelets. These results suggested that platelet abnormalities of TM rats are a typical characteristic of platelet SPD and are similar to those of FH rats, which are genetically different from TM rats. Therefore, TM rats may serve as a useful animal model for the study of platelet SPD.     

Spiranthes hachijoensis (Orchidaceae), a new species within the S. sinensis species complex in Japan,based on morphological,phylogenetic, and ecological evidence

The systematics of the Old World Spiranthes sinensis (Pers.) Ames species complex (Orchidaceae) has been complicated by its wide distribution and morphological variations. Within the species complex, S. australis Lindl. has been generally accepted as the only Spiranthes Rich. species distributed on the Japanese mainland. The present study provides morphological, phylogenetic, and ecological evidence for the recognition of S. hachijoensis Suetsugu as a new species of the S. sinensis species complex on the Japanese mainland. Spiranthes hachijoensis is morphologically similar to S. hongkongensis S.Y. Hu & Barretto and S. nivea T.P. Lin & W.M. Lin, sharing a degenerated rostellum, pollinia without a viscidium, and distinctly trilobed stigma. However, the taxon can be morphologically distinguished from S. hongkongensis by its glabrous rachis, ovaries, and sepals, and from S. nivea by its papillate labellum disc, larger papillate basal labellum callosities, and glabrous rachis, ovaries, and sepals. The autogamy and flowering phenology (i.e., earlier flowering) of S. hachijoensis are most likely responsible for premating isolation from the sympatric S. australis. A MIG-seq-based high-throughput molecular analysis indicated that the genetic difference between S. hachijoensis and its putative sister species S. sinensis is comparable to, or even greater than, the genetic difference between pairs of other species within the S. sinensis species complex. Our multifaceted approach strongly supports the recognition of S. hachijoensis as a morphologically, phenologically, phylogenetically, and ecologically distinct species.

     

Mouse Ly-31.1 is an alloantigenic determinant of alkaline phosphatase predominantly expressed in the kidney and bone

The mouse lymphocyte surface alloantigen, Ly-31, defined by monoclonal antibody N1.10 (IgG2b, k) and controlled by a gene locus closely linked to theAkp-2 locus on chromosome 4, was biochemically investigated. By employing a quantitative immunoassay system, it was found that the Ly-31.1-specific antibody detected an allotypic determinant of mouse alkaline phosphatase. Ly-31.1, i. e., mouse alkaline phosphatase, was expressed predominantly in kidney and bone and was also detected in placenta, lung, and testis. Concerning tumor cell lines, they varied in the amount of antigen present, with both T and B lymphoid lineages selectively possessing the antigen. In normal lymphoid tissues, lesser amounts of antigen were detected. The binding of mouse alkaline phosphatase to Ly-31.1-specific monoclonal antibodies was specific in nature. The Ly-31.1 antigen was immunoprecipitated from the lysates of surface-radiolabeled YAC-1 moloney leukemia cells, and appeared as a single band of about 78 000 under both reduced and nonreduced conditions on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Furthermore, treatment of tumor cell lines with phosphatidylinositol-specific-phospholipase C resulted in the removal of Ly-31 antigen from the cell surface. These results suggest that a gene cluster containing theLy-31 andAkp-2 loci which control the alkaline phosphatase is formed on mouse chromosome 4. The Ly-31 antigen is the first enzyme demonstrated to be a lymphocyte surface alloantigen.     

A method for histochemical demonstration of protein-bound amino groups by light microscopy

We have established an efficient method for the histochemical demonstration of protein-bound amino groups by light microscopy, using a ninhydrin or alloxan-thiocarbohydrazide-silver proteinate (NHY or ALX-TCH-SP) sequence followed by a physical development (PD) procedure. As a result of the present experimental studies on Carnoy's solution-fixed paraffin sections of a series of rat tissues, including three types of major salivary glands, liver, pancreas, stomach, duodenum, jejunum, colon, kidney, prostate, and spleen, the sensitivity and specificity of the new method were found to be sufficient. In the tissues tested, protein-bound amino groups were visualized by distinct brownish or blackish reaction products. Comparisons of the particular method with the NHY or ALX-Schiff methods employed hitherto have substantiated the fact that the former method leads to apparently higher visibility of reaction products than the latter.