The soybean β-amylase [α-1, 4-glucan maltohydrolase, EC. 3. 2. 1. 2] is composed of seven isozymes( Ⅰ`, Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ), and isozyme Ⅱ and Ⅳ are the main components among these. The purification of β-amylase isozymes from soybean whey were performed by ammonium sulfate fractionation, CM-Sephadex C-50 column chromatography, DEAE-Sephadex chromatography and Gel filtration. The resulted purity of β-amylase was throughly confirmed by electrophoresis, and then determined its isoelectric point and molecular weight. The results obtained were as follows ; 1. Five active fractions of soybean β-amylase were derived on CM-Sephadex C-50 column chromatography . 2. Seven active bands of β-amylase isozymes were detected by isoelectric focusing gel electrophoresis, and their isoelectric points ( Ⅰ` to Ⅵ) were 5.07, 5.15, 5.25, 5.40, 5.55, 5.70 and 5.93, respectively. 3. Isozyme Ⅱ and Ⅳ were main components of soybean β-amylase. 4. The molecular weights of both isozyme Ⅱ and Ⅳ were determined to be 56, 000 daltons by the result of SDS polyacrylamide gel electrophoresis. 5. Km values of main isozyme Ⅱ & Ⅳ for amylopectin were determined to be 2.25㎎/㎖, which suggest the same function of each isozyme.

Sweet potato β-amylase is a tetrameric enzyme consisting of four identical polypeptide chains with a molecular weight of 5.6×10 exp (4), though most of the other β-amylases are monomeric enzymes. But, the relationship between subunit structure and catalytic function of the enzyme is not known. This study was done to know what the function of the subunit structure of the enzyme is. We obtained the monomer from the enzyme by the treatment of SDS, alkali pH buffer and urea. But the monomer had not activity. We tried to prepare the active monomer from the enzyme by the modification with periodate-oxidized soluble starch. In the result, we succeeded in isolating an active monomer as an oxidized soluble starch-conjugated form. The active monomer had 57% of the original activity, 13.2% of the sugar and the molecular weight was estimated to be 6.4×10 exp (4). This results suggest that the tetrameric form of the enzyme is a most stable one and exists in nature, and the subunit structure of the enzyme plays an important role in stabilization but not catalytic function.

Inclusion complex formation of octyldimethyl p-aminobenzoate with β-cyclodextrinin aqueous solution and in the solid state was studied by the solubility method, spectroscopic (UV, FT-IR) and X-ray diffractornetry. The solid complex of octyldimethyl p-aminobenzoate with β-cyclodextrin was obtained in molar ratio of 1:2 (guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and β-cyclodextrin in water at 25℃. The results indicated that the solubility of the guest molecule was higher by the formation of β-cyclodextrin inclusion complex.

We examined the characteristics of the SNU uvby, Hβ Hβ filter system through the computation of theoretical photometric indices and the transformation of the observed instrumental system to the natural and standard systems.

In this study, a biodegradation model of based on molecular cellulose was established. It is a mathematical, kinetic model, assuming that two major enzymes randomly break glycosidic bonds of cellulose molecules, and calculates the number of molecules by applying the corresponding probability and degradation reaction coefficients. Model calculations considered enzyme dose, cellulose chain length, and reaction rate constant ratio. Degradation increased almost by two folds with increase of temperature (5℃→25℃). The change of degradation was not significant over the higher temperatures. As temperature increased, the degradation rate of the molecules increased along with higher production of shorter chain molecules. As the reaction rates of the two enzymes were comparative the degree of degradation for any combinations of enzyme application was not affected much. Enzyme dose was also tested through experiment. While enzyme dose ranged from 1 mg/L to 10 mg/L, the gap between real data and model calculations was trivial. However, at higher dose of those enzymes (>15 mg/L), the experimental result showed the lower concentrations of reductive sugar than the corresponding model calculation did. We determined that the optimal enzyme dose for maximum generation of reductive sugar was 10 mg/L.

This study was designed to assess the possibility of using medicinal plant extracts as β-lactamase inhibitors to control antibiotic-resistant Staphylococcus aureus. The susceptibilities of S. aureus ATCC 15564 (SAWT), ciprofloxacininduced S. aureus ATCC 15564 (SACIP), oxacillin-induced S. aureus ATCC 15564 (SAOXA), and clinically-isolated S. aureus CCARM 3008 (SACLI) to ampicillin were determined in the absence and presence of medicinal plant extracts, including Cleyera japonica (CJ), Carpinus laxiflora (CL), Euphorbia helioscopia (EH), Euscaphis japonica (EJ), Oenothera erythrosepala (OE), and Rosa multiflora (RM). The phenotypic change in the clear inhibition zones around ampicillin disc was observed for SAWT, SACIP, and SAOXA, indicating the production of ampicillinase. Compared to the controls, the MICs of ampicillin against SAWT, SACIP, and SAOXA were decreased from 4 to 0.5 ㎍/mL in the presence of CL, 16 to 4 ㎍/mL in the presence of RM, and 32 to 2 ㎍/mL in the presence of CL, EH, and RM, respectively. The medicinal plant extracts, OE, EJ, and CL, effectively inhibited the β-lactamase activities of SAWT (78%), SACIP (57%), and SAOXA (76%) when compared to the control. This results suggest that the medicinal plant extracts can be used as BLIs to control the antibiotic-resistant S. aureus.

이상의 연구 결과로 먹넌출 열매 추출물은 GSK3β 의존성 Cyclin D1 단백질의 분해를 통해 대장암세포의 생육 억제와 관련이 있는 것으로 확인된다. 본 결과는 대장암의 항암제 개발을 위한 소재로 먹넌출 열매의 활용이 가능할 것으로 판단된다.

이상의 연구 결과로 미루어 볼 때, 도깨비부채 잎(RPL)은 β -catenin의 분해 유도를 통해 대장암, 유방암, 폐암, 전립선암 및 췌장암 세포의 생육을 억제하는 것으로 나타났다. 본 결과는 도깨비부채 잎의 항암을 위한 대체보완소재 및 천연 항암제 개발을 위한 소재로 활용이 가능할 것으로 판단된다. 그러나 추가적 연구를 통해 도깨비 부채 잎의 항암 활성물질의 분석연구가 필요할 것으로 사료된다.