Comparative study on mucus glycoproteins in rat stomach and duodenum

The density of mucus glycoprotein compared to that of the corpus, antrum and duodenum was; 1.52, 1.49 and 1.57 g/ml respectively. Carbohydrate composition of gastrointestinal mucus glycoprotein consisted of N-acetylgalactosamine, N-acetylglucosamine, galactose, fucose and sialic acid. Ratios of carbohydrate composition among corpus, antral and duodenal mucus glycoproteins differed. The average length of an oligosaccharide was found to be about 12-13, 14 and 10 sugars in the corpus, antrum and duodenum, respectively. In the corpus, the amino acid content was found to have the following quantitative order: Thr greater than Ser greater than Glx = Pro; in the antrum: Thr greater than Ser greater than Glx; and in the duodenum: Thr greater than Ser greater than Pro. Corpus, antral and duodenal mucus glycoproteins have the blood-group A antigen; antral mucus glycoprotein in particular exhibited strong blood-group A activity.     

Growth Analysis of Sumatran Monophyllaea, Possessing Only One Leaf Throughout Perennial Life

Abstract Growth and allometry were analyzed for populations of Monophyllaea hirtella Miq and M. horsfieldii R. Br. (Gesneriaceae), forest floor herbs that have only one cotyledonous leaf throughout life, in an equatorial rain forest in West Sumatra. Monophyllaea populations consisted of individuals of various sizes up to 30 g dry weight and 50x70 cm in leaf width and length. The relative growth rate (RGR) declined with size to an asymptotic value of 0.015–0.018 gg^-1 week^-1 for large individuals at sexual maturity (>2 g dry weight). The size-RGR relation did not differ among observations at three differen times of year and between two species in different habitals, indicating that it takes 4.6 years for seedlings to attain sexual maturity and 6.4 years to reach 10 g dry weight. Irrespective of embryonic organization of Monophyllaea , clear allometry existed among organs. Net assimilation rate was constant for juveniles and increased with size for adults. Decline of both the specific leaf area and the ratio of assimilate allocation to leaf caused the decrease of RGR with size. Reproductive allocation was 31% to reproductive organs and at most 5% to seeds in net production in a large individual of 20 g dry weight.     

Meiosis-specific transcripts of a DNA component replicated during chromosome pairing: homology across the phylogenetic spectrum

In meiotic cells of Lilium, a group of single or low copy number DNA sequences that constitute about 0.1-0.2% of the genome do not replicate during the premeiotic S-phase but do so at zygotene in coordination with chromosome pairing. An appreciable fraction of these sequences has now been found to be transcribed into poly(A)+ RNA when chromosomes initiate the pairing process. This "zygRNA" has not been detected in nonmeiotic tissues. Even within the meiocytes, zygRNA is not detectable prior to leptotene or beyond midpachytene. S1 nuclease digestion of mouse spermatocyte nuclei selectively released zygDNA, which hybridizes with lily zygRNA. zygRNA has not been detected in mouse somatic tissues. The profile of zygRNA formation and disappearance in mouse spermatocytes is very similar to that of zygRNA in lily meiocytes.     

Enhancement of dengue virus infection in cultured mouse macrophages by lipophilic derivatives of muramyl peptides

Dengue virus multiplication in cultures of a murine myelomonocytic cell line (WEHI-3) as well as mouse peritoneal macrophages was enhanced by treatment of the cells with lipophilic derivatives of muramyl peptides for 2 or 3 days before virus inoculation, but not for 2 hr before virus inoculation or during the adsorption period. The infection-enhancing activity of the materials was dependent on their chemical structure, correlating with their immunoadjuvanticity. The infection enhancement in WEHI-3 cells was due primarily to an increase in the number of virus-infected cells which was accompanied by an increased cellular capacity to bind latex particles to their cell surfaces.     

Influence of heme-surrounding amino acid residues on the manganese (V)-nitrido bond in manganese-substituted hemoproteins: resonance Raman evidence for porphyrin core expansion and reduction of the manganese(V)-nitrido stretching force constant

Nitridomanganese(V) protoporphyrin IX was prepared by hypochlorite oxidation of the corresponding manganese(III) protoporphyrin IX derivative in the presence of ammonium ion and by photolysis of the corresponding azidomanganese(III) complex. Myoglobin and horseradish peroxidase containing this novel protoporphyrin derivative were prepared for the first time. These remarkably stable species were examined by electronic absorption, electron paramagnetic resonance, and resonance Raman spectroscopies. The MnV-N stretching modes of the nitridomanganese(V)-substituted myoglobin and horseradish peroxidase were observed at 1010 and 1003 cm-1, respectively, by resonance Raman spectroscopy, while the MnV-N stretching frequency for nitridomanganese(V) protoporphyrin IX in 0.1 N aqueous NaOH was found at 1046 cm-1. The equilibrium dissociation energies of MnV-N bonds in these complexes were estimated from vibrational overtone spacings by introducing the Morse potential energy function, were found to be around 4.5 eV, and seemed independent of the surroundings of the manganese porphyrin, although its force constant decreased from 7.3 to 6.7 mdyn/A upon incorporation into apoprotein. The porphyrin ring modes of these nitridomanganese(V) derivatives were influenced greatly upon incorporation into apoproteins, suggestive of the occurrence of porphyrin core expansion. Upon this core expansion the MnV center moves into the mean plane of porphyrin plane, but the access of nitrido (N) toward MnV is restricted due to a steric hindrance from porphyrin pyrrole nitrogens. The resulting stretched MnV-N bond might cause lowering of the MnV-N stretching frequency upon incorporation into apoprotein.     

Involvement in Meiotic Prophase of H1 Histone Kinase and p34cdc2 Homologues in Lily (Lilium longiflorum) Microsporocytes

We have taken advantage of the synchrony of meiotic prophase I in Lilium microsporocytes to investigate the presence and involvement in four stages of meiotic prophase I (leptotene, zygotene, pachytene, and diplotene) of the p34^cdc2 H1 histone kinase, a component of MPF and a key participant in division control in other eukaryotes. H1 kinase activity showed a peak pattern during meiotic prophase I with the highest kinase activity at pachytene. A monoclonal antibody directed against a highly conserved region of p34^cdc2 (termed the 'PSTAIR') recognized three major protein forms by immunoblotting. The highest level of the fastest-migrating form was observed at pachytene, coinciding with the highest activity of H1 kinase. Both the proteins recognized by the anti-PSTAIR antibody and H1 histone kinase activity were retained on beads conjugated with p13^suc1, a protein known to physically associate with p34^cdc2. These observations suggest that p34^cdc2 or protein(s) highly homologous to p34^cdc2 is a component of Lilium H1 histone kinase and plays a role in regulating meiotic prophase I.     

Application of trinitrophenylation for the measurement of alpha-amino residues resulting from peptic digestion.

A sensitive and precise method for the measurement of peptic activity on protein substrate is described. alpha-Amino residues formed by pepsin digestion are photometrically measured by comparing the absorbances of digested and nondigested material which has been trinitrophenylated. The usual problem of high reagent-blank absorbance is eliminated by using an anion exchange resin, Dowex 1-X8. In contrast to Anson's method, the procedure requires only 1/100 the quantity of protein substrate for analysis. It was proved to be particularly useful for the estimation of initial rates of proteolysis.