Effects of exogenous hemin on the niacin content of aerobically grown Saccharomyces uvarum

In Saccharomyces uvarum aerobically grown in the tryptophan-added medium, the niacin content started to increase when both tryptophan and glucose in the medium had almost been exhausted. In the kynurenine-added medium, the niacin production occurred immediately after incubation started. Hemin added to the medium enhanced total niacin production by increasing the amount of tryptophan metabolized via the kynureninase flux. The results suggest that the niacin biosynthesis from tryptophan was regulated by catabolite repression, which was alleviated by exogenously added hemin.     

Identification of the replication region of Lactobacillus acidophilus plasmid pLA103

Abstract The structure of the region necessary for replication of the plasmid pLA103 from Lactobacillus acidophilus TK8912 has been characterized. Sequence analysis revealed that the replication region contained an open reading frame (OrfA) encoding a 282-amino acid peptide preceded by a 22-bp tandem repeat sequence region. The predicted OrfA protein showed homology to the replication protein of a plasmid from Pediococcus halophilus . The plasmid containing the repeat sequence region preceding OrfA was able to replicate in the Lactobacillus host when provided with OrfA in trans , suggesting that the repeat sequence region contains the origin sequence essential for the pLA103 replication.     

Altered immune responsiveness in patients with chronic glomerulonephritis

In order to detect abnormalities in humoral immunity and to determine immunogenetic traits underlying chronic glomerulonephritis, sera from 260 patients who had chronic glomerulonephritis and who were undergoing hemodialysis were tested for naturally occurring antibodies against mycoplasma and 22 different viruses. Among the 23 microorganisms tested, antibody titers were significantly lower against 12, higher against 3, and no different against 8 when compared with titers of 43 normal subjects. The data were analyzed further by plotting each in a 23-dimensional space according to their standardized antibody titers. Multivariate cluster analysis by the Ward's method revealed 3 large clusters differing from each other in natural antibody titers, and one of the clusters included 74% of the normal controls, while two other distinct clusters comprised the majority of the patients. The level of BUN, creatinine, and duration of hemodialysis treatment did not differ significantly among patients in these three different clusters. Our study suggests that patients with chronic glomerulonephritis being treated by hemodialysis have altered levels of naturally occurring antibodies to microorganisms. This alteration is not caused by just the uremic state or hemodialysis but immunogenetic regulation may also play a part.     

An accumulation of galactocerebroside in kidney from mouse globoid cell leukodystrophy (twitcher)

The twitcher mouse is genetically determined mutant characterized by a deficiency of galactocerebroside beta-galactosidase. In this study, a significant accumulation of galactocerebroside was demonstrated in twitcher mouse kidney. The data suggest that mouse Krabbe's disease is not only involved in CNS, but also in visceral organs.     

Lignin characterization of rice CONIFERALDEHYDE 5‐HYDROXYLASE loss‐of‐function mutants generated with the CRISPR/Cas9 system

The aromatic composition of lignin is an important trait that greatly affects the usability of lignocellulosic biomass. We previously identified a rice (Oryza sativa) gene encoding coniferaldehyde 5‐hydroxylase (OsCAld5H1), which was effective in modulating syringyl (S)/guaiacyl (G) lignin composition ratio in rice, a model grass species. Previously characterized OsCAld5H1‐knockdown rice lines, which were produced via an RNA‐interference approach, showed augmented G lignin units yet contained considerable amounts of residual S lignin units. In this study, to further investigate the effect of suppression of OsCAld5H1 on rice lignin structure, we generated loss‐of‐function mutants of OsCAld5H1 using the CRISPR/Cas9‐mediated genome editing system. Homozygous OsCAld5H1‐knockout lines harboring anticipated frame‐shift mutations in OsCAld5H1 were successfully obtained. A series of wet‐chemical and two‐dimensional NMR analyses on cell walls demonstrated that although lignins in the mutant were predictably enriched in G units all the tested mutant lines produced considerable numbers of S units. Intriguingly, lignin γ‐p‐coumaroylation analysis by the derivatization followed by reductive cleavage method revealed that enrichment of G units in lignins of the mutants was limited to the non‐γ‐p‐coumaroylated units, whereas grass‐specific γ‐p‐coumaroylated lignin units were almost unaffected. Gene expression analysis indicated that no homologous genes of OsCAld5H1 were overexpressed in the mutants. These data suggested that CAld5H is mainly involved in the production of non‐γ‐p‐coumaroylated S lignin units, common in both eudicots and grasses, but not in the production of grass‐specific γ‐p‐coumaroylated S units in rice.     

Synthesis and biological evaluation of molecular probes based on the 9-methylstreptimidone derivative DTCM-glutarimide

Molecular probes based on 3-[(dodecylthiocarbonyl)methyl]glutarimide (DTCM-glutarimide) were synthesized and assessed for inhibitory activity against LPS-induced NO production. Among the probes examined, several derivatives exhibited potential for use in determining the target proteins of DTCM-glutarimide.