Analysis of soot formation in a rapeseed oil-fueled diffusion flame: focusing on the importance of soot in Nara sumi.

Nara sumi is a traditional Japanese craft that has been handed down in Nara since ancient times, and now plays a major role as a regional resource. Soot is considered to be one of the most important materials for its quality. However, the making process has been supported solely by the rule of thumb for craftsmen for many years, and there is very little scientific understanding of that. Therefore, we are focusing on the soot formation process in this study. Soot was collected from different heights in a rapeseed oil-fueled diffusion flame and analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy. As a result, it was confirmed that the formation of the soot shape completes at the bottom of the outside of the flame and that the shape does not change thereafter. It was also confirmed that the oxidation of soot occurs at the bottom of the outside of the flame. These results are expected to contribute to the further scientific understanding of the soot formation process.

Porcine germinal angiotensin I-converting enzyme: isolation, characterization and molecular cloning.

Germinal angiotensin I-converting enzyme (gACE) was purified to homogeneity from porcine seminal plasma. The molecular weight of the purified enzyme was calculated to be 182,000 on non-denaturing PAGE and 94,000 and 93,000 on SDS-PAGE in the absence and presence of beta-ME, respectively. These findings suggest that the enzyme is composed of two identical subunits in seminal plasma. The K(m), V(max), K(cat) and K(cat)/K(m) values of gACE at optimal pH (pH 7.2) were 680 microM, 1.0 micromol/mg/min, 33.1 s(-1) and 4.87 x 10(4) s(-1) M(-1) for Z-Val-Lys-Met-MCA, respectively. gACE was potently inhibited by EDTA, 1,10-phenanthroline, captopril and lisinopril, and it promptly released the dipeptides His-Leu and Phe-Arg from angiotensin I and bradykinin. Met- and Leu-enkephalins, neuromedine B and beta-neo-endorphin were also good natural substrates for gACE. We determined the structure of gACE cDNA from the porcine testis, and deduced the amino acid sequence of gACE. The cDNA is composed of 2508 bp of nucleotides in length and encodes 745 amino acids in the coding region. The overall homology of amino acid sequences between porcine, human, sheep and rat gACEs is 72.6 to 84.7%. Zinc-binding motif, chloride-binding site and positions of cysteine residues were well conserved.

Time-dependent self-assembly of 31-epimerically pure and mixed zinc methyl bacteriopheophorbides-d in an aqueous THF solution.

The self-aggregation process of 3(1)-epimerically pure and mixed zinc methyl bacteriopheophorbides-d (ZMBPhes-d) was examined by stopped-flow technique. A 33(v/v)% tetrahydrofuran (THF) - water solution of ZMBPhe-d was rapidly mixed with a 7(v/v)% THF - water solution to form a chlorosome-type aggregate with a red-shifted Qy band around 700 nm. We observed a rapid autocatalytic aggregation in a subsecond time scale. Aggregates of the 3(1)R epimer increased with a change in the Qy absorption maximum from 698 to 705 nm, suggesting that small aggregates formed as intermediate species. In addition, the rate of aggregation was dependent on the stereochemistry at the 3(1)-position of ZMBPhe-d; the 3(1)R epimer self-aggregated more rapidly than the 3(1)S epimer.

Coaggregate of amphiphilic zinc chlorins with synthetic surfactants in an aqueous medium to an artificial supramolecular light-harvesting system.

Aqueous assemblies of zinc chlorins possessing a nonionic (oligo)oxyethylene, a cationic quaternary ammonium or an anionic sulfonate group were prepared in the presence of a synthetic surfactant. The nonionic zinc chlorin formed aggregates when admixed with a nonionic surfactant such as Triton X-100 to give a highly ordered oligomeric J-aggregate similarly as natural bacteriochlorophyll-c or d does in a chlorosome. In addition, the coassemblies of the cationic zinc chlorin with an anionic surfactant and of the anionic zinc chlorin with a cationic surfactant gave large oligomers of these chlorophyllous pigments. The structures of hydrophilic groups in both the zinc chlorin and surfactant molecules controlled their aqueous coassemblies.

Legumain from bovine kidney: its purification, molecular cloning, immunohistochemical localization and degradation of annexin II and vitamin D-binding protein.

Legumain (asparaginyl endopeptidase) was purified to homogeneity from bovine kidneys. The molecular mass of the purified enzyme was calculated to be 34000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of beta-mercaptoethanol. The enzyme rapidly hydrolyzed the substrate Z-Ala-Ala-Asn-MCA and was strongly inhibited by N-ethylmaleimide, p-chloromercuribenzene-sulfonic acid, Hg(2+) and Cu(2+). The amino acid sequence of the first 26 residues of the enzyme was Gly-Gly-Lys-His-Trp-Val-Val-Ile-Val-Ala-Gly-Ser-Asn-Gly-Gln-Tyr-Asn-Tyr-Arg-His-Gln-Ala-Phe-Ala-Asp-His-. This sequence is highly homologous to the sequences in the N-terminal of pig kidney legumain. We screened a bovine kidney cortex cDNA library using a DNA probe that originated from rat legumain, and we determined the bovine kidney cDNA structure and deduced the amino acid sequence. The cDNA is composed 1934 bp and encodes 433 amino acids in the coding region. The enzyme was strongly stained in the proximal tubules of the rat kidney in an immunohistochemical study. Vitamin D-binding protein which is known to be a ligand to megalin existing in the proximal tubules, was cleaved in a limited proteolytic manner by bovine kidney legumain. These results suggested that legumain contributes to the processing of macromolecules absorbed by proximal tubule cells. The enzyme also cleaved an N-terminal synthetic peptide of bovine annexin II (Gly(24)-Ser-Val-Lys-Ala-Tyr-Thr(30)-Asn-Phe-Asp-Ala-Glu(35)-Arg-Asp(37)) at a position between Asn(31) and Phe(32). The amino-terminal domain of annexin II has p11 subunit binding sites and phosphorylation sites for both pp60(src) and protein kinase C. This suggests that legumain plays an important role in inactivation and degradation of annexin II, which is abundant in the receptor-recycling compartments of endosomes/lysosomes.