An apoptotic inducer, aralin, is a novel type II ribosome-inactivating protein from Aralia elata.

We recently found that aralin, a novel cytotoxic protein consisting of two subunits, from Aralia elata selectively induces apoptosis in transformed cells as compared to normal cells. Here we report that aralin is a lectin specific for galactose (Gal) and its derivatives, and possesses RNA N-glycosidase activity as a new type II ribosome-inactivating protein (RIP). The RNA N-glycosidase activity of aralin was detected in cell-free and whole cell systems by the generation of an R-fragment from 28S rRNA.

Production of aralin, a selective cytotoxic lectin against human transformed cells, in callus culture of Aralia elata.

Recently we found that aralin, a novel lectin, from Aralia elata selectively induces apoptosis in human virus-transformed and cancer cells compared with normal cells. To overcome the reduction of aralin biosynthesis according to the development of leaves, we established callus tissues from the young shoots. The N-terminal amino acid sequence and immunochemical analyses revealed that ca-aralin, an aralin synthesized in the callus, was structurally identical with aralin except for the glycosylation of the B chain.

Partial purification of an enzyme hydrolyzing indole-3-acetamide from rice cells.

The activity of indole-3-acetamide (IAM) hydrolase from rice cells was enriched ca. 628-fold by gel filtration and anion exchange column chromatography. The molecular masses of the IAM hydrolase estimated by gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis were approximately 50.

Ursane- and oleanane-type triterpenes from Ternstroemia gymnanthera callus tissues.

An investigation on the constituents of the callus tissues of Ternstroemia gymnanthera has led to the isolation of five phytosterols, 15 known triterpenoids, and four new triterpenoids (1-4). The new compounds were characterized by spectroscopic study as 3-epi-corosolic acid lactone (2 alpha,3 alpha-dihydroxyurs-11-en-13 beta,28-olide) (1), 3-epi-ternstroemic acid (2 alpha,3 alpha-dihydroxyurs-12-en-11-on-28-oic acid) (2), ternstroemic acid (2 alpha,3 beta-dihydroxyurs-12-en-11-on-28-oic acid) (3), and gymnantheraic acid (2 alpha,3 alpha-dihydroxy-11 alpha-methoxyurs-12-en-28-oic acid) (4). The isolated triterpenes were compared with those from actinidiaceous plant callus tissues from a chemotaxonomic point of view.

Inhibition of DNA polymerases and DNA topoisomerase II by triterpenes produced by plant callus.

We found that some triterpene compounds could not only selectively inhibit the activities of mammalian DNA polymerase alpha (pol alpha) and beta (pol beta), but could also potently inhibit DNA topoisomerase II (topo II) [Biochem. J. 350 (2000) 757].

Root, root hair, and symbiotic mutants of the model legume Lotus japonicus.

To gain an overview of plant factors controlling nodule number and organogenesis, an extensive screening using model legume Lotus japonicus was carried out. This screening involved 40,000 M2 seeds, and 32 stable mutant lines were isolated. From these, 16 mutant lines maintaining the phenotypic variation were selected and genetically analyzed.

A Digital Filter for the State Estimation of Impulsive Noise Under the Existence of a Background Noise and its Experiment in the Work Environment.

In the actual work environment, a specific objective noise, like machine and industrial noises, shows impulsive fluctuation form. Furthermore, it often occurs that a specific noise is partially or completely contaminated by background noise. In that case, the fluctuation wave form of the specific noise has to be estimated moment by moment in order to evaluate and/or improve the work environment.