Pectinase was isolated from culture medium of Bacillus sp. BS-214 and purified 105-fold with 3.4% yield by ammonium sulfate precipitation, gel filteration using Sephadex G-75 and DEAE-cellulose followed by gel filteration through Sephadex G-100. The molecular weight of the purified enzyme was estimated to be about 43 kDa on SDS-PAGE and by gel filtration, indicating that the enzyme is a monomer. the optium pH and temperature of the enzyme were 9.0 and 55$^{\circ}C$, respectively. the enzyme was stable at 60$^{\circ}C$ for 30min and in a pH range from 7.5 to 10.5 for 12 h ant 4$^{\circ}C$. The enzyme activity was highly enhanced by Ca2+, and also K+, Li+ and Na+showed a positive effect, while stongly inhibited by Zn2+ and Hg2+.

Salmonella typhimurium is a causative agent of the common worldwide disease, salmonellosis. To identify putative invasion genes involved in Samonella infections, a S. typhimurium cosmid library was constructed in noninvasive E. coli DJl. The invasion efficiencies of the cosmid library for cultured HEp-2 and HeLa cells were estimated by tissue-culture invasion assay. 2 out of 1,000 transductants, DHl(pSI623) and DHl(pSI511) were able to invade the cells. Compared to E. coli by DHl(pSI511) increased 25- and 33 fold, respectively. The invasion efficiencies of HeLa cells by DHl(pSI623) increased 31- and 35 fold, respectively. This illustrates that the cosmid clones, DHl(pSI623) and DHl(pSI511) could harbor the invasion determinants derived from genomic DNA of S. typhimurium 82/6915, conferring the invasive characters for the cells.

To develope the genetic source of oak wild silkworm, Antheraea yamamai, the cDNA library was constructed with poly A+ mRNA isolated from posterial silk gland of fifth instar larvae. Titer of the cDNA library was about 5.1$\times$105 pfu in total. We presumed that the titer covered almost all transcripts existed in Antherea yamamai. From cDNA library of Antheraea yamamai, fibroin heavy chain gene, which is specifically expressed from posterial silk gland of Antheraea yamamai, was screened using oligonuclotide probe specific to alanine rich motif of fibrin heavy chain gene of Antheraea pernyi. As a result, fibroin clones isolated from 5$\times$104 plaques showed the highest homolgy (95%) with that of Antherea pernyi in nucleotide of Anthereaea yamamai and Bombyx mori shows that there is no homologous sequence in the 3+ partial 채야후 region Genomic southern hybridization suggested that one copy is present. Northern hybridization showed that fibroin transcript was approximateely 9 kb in length.

Variation at 25 allozyme loci in Korean wateralder (Alnus hirsuta Rupr.) from nine distinct populations was measured to estimate the amount and pattern of genetic diversity and population structure. The mean genetic diversity within population was 0.166. Korean alder populations have slightly high levels of genetic diversity compared to those present in associated temperature-zone species and two Canadian alder species. Among population s genetic differentiation accounted for an significant 9% of the total variation. High gene flow(Nm=2.63) was observed. Analysis of fixation indices, calculated for all polymorphic loci in each population, showed a substantial deficiency of heterozygotes relative to Hardy-Weinberg expectations. The mean GST value A. hirsuta in Korea (GST = 0.087) is similar to those of A. rogosa in Canada (GST = 0.052). These low values of GST in two countries. reflecting little spatial genetic differentiation, may indicate extensive gene flow (via pollen and/or seeds) and/or recent colonization. These factors reduce the effect of geographic isolation of breeding and the chance for genetic divergence. A pattern of increasing is observed with increasing rainfall per year. Regression analysis indicates that 54% (F = 4.67) of the variability observed can be explained by this relationship.

Mono-ADP-ribosylation, catalyzed by ADP-ribosyltransferases, is a post-translational modification of proteins in which the ADP-ribose moiety of NAD is transferred to an acceptor protein. Previously, we have identified and cloned a glycosylphosphatidylinositol-linked ADP-ribosyltransferase (Yac-1) from mouse lymphoma cells. Yac-1 enzyme contains three regions (region I,II,III) similar to those found in several bacterial toxins and vertebrate ADP-ribosyltransferases. Site-directed mutagenesis was performed to verify the role of Glu 233 in region III. Mutants E233Q, E233D and E233A were inactive for ADP-ribosyltransferase activity. Thus Glu 233 in Yac-1 is essential for enzyme activity, suggesting that Glu 233 in Glu-rich motif near the carboxy terminus plays a catalytic role in ADP-ribosyltransferase activity.

For the rapid diagnosis of vibriosis in penaeid shirmp, the indirect fluorescent antibody technique(IFAT) was established to detect Vibrio alginolyticus. The titers of the antisera used for this experiment were above 1280. Vibrio alginolyticus possesses the specific antigen, and also have antigens shared with other strains. When an V. alginolyticus-infected adult shirmp was tested by IFAT, V. alginolyticus was detected mainly in the muscle tissues near the injection point and the haemolymph but only few in other tissues. This result indicates that the pathogen bacteria could be detected by IFAT. Thus, it is suggested IFAT is more convenient and sensitive method than conventional plate method for the diagnosis of induced Vibrio infection in the penaeid shrimps.

Solitary long terminal repeats(LTRs) of human endogenous retrovirus K family(HERV-K) have been found to be coexpressed with sequences of closely located genes. It has been suggested that HERV-K LTR-like elements entered the primate genome approximately 33-40 million years ago. WE investigated the presence of HERV-K LTR elements in New World monkeys using PCR amplification. Six LTR elements of HERV-K family were identified from New World monkeys, represented by the squirrel and night monkeys. They showed a high degree of sequence homology(96-99%) with the human-specific HERV-K LTR elements. Phylogenetic analysis reveals that an LTR element (SM-1) from the squirrel monkey and another LTR element (NM-1) from the night monkey are very closely related to the human-specific HERV-K LTR elements with low degree of divergence. This finding suggests that some of LTR elements of HERV-K family have recently been proliferated in New World monkeys. A sequence in chromosome Xq26(AL034407) \ulcorner contains an HERV-K LTR element was shown to be present in the human genome, but is absent in the bonobo, chimpanzee, gorilla, orangutan, and gibbon. It has more than 99% homology to other human-specific HERV-K LTR elements. This sequence thus represents and isolated insertion of an evolving class of elements that may have made a particular contribution to human genomic plasticity.

Testis-specific protein Y(TSPY) is thought to play an important role during spermatogenesis in primates. The Arg and Lys-rich region of TSPY was implicated as a potential DNA binding site in the human and Japanese monkey. In the study, we investigated this further through looking at the putative amino acid sequences of Arg and Lys-rich region of TSPY gene from seven species of gibbons, five species of Old World monkeys and five species of New World monkeys. A comparison with those of the human and Japanese monkey revealed that the Arg and Lys-rich motif was hightly conserved in various primates. This finding suggests that a possible role for the Arg and Lys-rich motif in primate TSPY is DNA recognition. The functional implications for TSPY are discussed in the light of this and previous findings.

The SNF2/SW ATPase/helicase family comprises proteins form a variety of species with in vivo functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. Here, we reported the characterization of h게2+gene which was iolated by PCR amplification using the conserved domain of SNF2 motifs. Sequence analysis of PCR product showed striking evolutionary conservation among the SNF2 family of proteins. Two transcripts of 6.7 and 3.4 Lb were detected by Northern blot analysis. furthermore, the intensities of these two bands were increased by ultraviolet(UV) irradiation. These results indicate that the hrp2+ is a novel member of the SNF2 family of proteins and is one of the UV-inducible genes in S. pombe. To determine the level of transcripts of hrp2+ gene during cellular growth, Northern blot analysis were performed. This result indicates that the level of hrp2+transcript reached its maximum before cells entered the exponential growth phase. This suggests that hrp2+ gene is experssed mainly at the early stage of cell growth.

Nonactin, known as an ionophore antibiotic, was antagonized by the actibity of quercetin, an oxygen radical scavenger. This compound generated superoxide radicals in Bacillus subtilis lysates. A recombination-deficient mutant strain of B. subtilis was more sensitive than a wild strain, and this hypersensitivity was reduced in the presence of dithiothreitol as an antioxidant. These results suggest that superoxide radical is important in the antibacterial action of this agent.

The cytogenetic pattern of autosome and sex chromiosome after Giemas staining were examined in the hybrids between two sibling species, Drosophila melanogaster and D. simulans. The analysis of karyotype in the hybrid female between D. melanogaster females and D. simulans males could be easily distinguished the characteriation of eight chromosomes from bothe species, especially with regard to X chromosomes. The lagging duplication of Y chromosome was investigated in the interspecific hybrid males from the cross between female of Drosophila melanogaster(OR) and males of D. simulasn (K18). On the other hand, the X chromatids of D. simulans were loosely separated in the early stage of anaphase.

In many cases of human cancer, the appearance of hypersialylated glycan structures is related to a precise stage of the disease ; this may depend on the elebated sialyltransferase activity during carcinogenesis. The aim of this study was to investigate the inhibitory effects of Oriental medicinal herbs on enzymatic activities of two kinds ofsialyltransferase, Gal $\beta$ 1,3GalNAc$\alpha$2,3-sialyltransferase(ST3Gal I) and Gal $\beta$ 1,4GlcNAc $\alpha$2,6-sialyltransterases(ST6Gal I), which are well known as glycosyltransterases associated with cancer. The aqueous extracts of Scutellaria Baicalensis Georgi, Coptidis Rhizoma, Glycyrrhiza urlensis Fisch, Bupleuri Radix and Platycodi Radix were prepared and tested, respectively. At concentration of 100$\mu$g, Glycyrrhiza uralensis Fisch showed the highest inhibitory effects(about 42% and 57%, respectively) on ST3Gal Iand ST6Gal Iactivities. ST3GAl I was inhibited about 23% by Scutellaria baicalensi G댁햐, but not by the other samples, whereas ST6Gal I was inhibited about 20% and 40%,respectively, by Scutellaria baicalensis Georgi and Bupleuri Radix. All inhibitory effects were obtained in a concentration-dependent manner.

${\beta}$-catenin, which plays a critical role in both the cytoskeleton and in transcriptional regulation in variousadherent cell types, undergoes degradation during adherent cell apoptosis. Although ${\beta}$-catenin has been reported to be present in Jurkat T-acute lymphoblastic leukemia cells, the regulation of ${\beta}$-catenin in hematologic malignancies have not been examined. The data presented here demonstrate that treatment of the T cell leukemia Jurkat iwht the apoptosis inducer anti-Fas induced proteolytic cleavage of ${\beta}$-catenin. ${\beta}$-catenin was cleaved at both the N- and C-terminus after anti-Fas treatment. Cleavage of intact ${\beta}$-catenin was completely inhibited by caspase selective protease inhibitors. These data demonstrate that ${\beta}$ -catenin proteolysis is triggered by the cross-linking of the Fas receptor on Jurkat cells and subsequent activation of caspase protease. There was a clear accumulatio of the large proteolytic fragment in Jurkat cells treated with lactacystin of ALLM. These are potent inhibitors of proteasome and calpain. these results suggest that both the proteasome and clapain may recognize the large ${\beta}$-catenin fragment as a substrate fot further degradation and that these pathewasy may act downstream of scapase in response to Fas receptor activation. Therefore, we suggest that ${\beta}$-catenin may play a role in promoting Jurkat survival.

Insoluble phosphate-solubilizing bacteria are routinely screened by a plate assay method using Pikovskaya agar and a modified Pikovskaya medium. A modified Pikovskaya medium to improve the clarity of the yellow-colored halo has not necessarity improved the plate assay. Colonies of phosphate-solubilizing bacteria tested could be redily selected after 48 h of incubation by green-colored colony formation on plate in which bromcresol green(BCG) was included. Among them, two bacterial strains did not produce distinct yellow halos after 48 h of incubation. We suggest that the green colony formation on plate medium containing BCG is advantageous ofr rapid isolating phosphate-solubilizing bacteria directly from soil.