Heterologous plasmid DNA 의 transformation에 있어서의 細胞膜 蛋白質의 기능에 對하여

徐正塤,洪淳德,李麟九,金英浩 慶北大學校 1983 論文集 Vol.36 No.-

Terramycin resistance plasmid DNA and Streptomycin resistance plasmid DNA have been prepared from Streptomyces rimosus and E. coli KPM 105, respectively, by phenol extraction of lysozyme-lysed cells. And the plasmid DNA was introduced into B. subtilis KPM 73, B. subtilis BD 224, B. subtilis 110, B. subtilis RM 125, B. amyloliquef aciens and B. megaterium IAM B425 by transformation. The variable characters affecting heterologous plasmid transformation, and the functions of competence factor and binding factor existing in the recipient cell surface were futhermore studied. Terramycin resistance plasmid was well transformed into Bacillus subtilis KPM 73 and B. subtilis RM 125, and Streptomycin resistance plasmid was well transfomed into B. subtilis BD 224, B. subtilis 110 and B. megaterium IAM B 425 at high frequency. The high frequency of plasmid transformation was obtained at 4 hr of incubationin growth medium. 20 to 50 min in competence medium, and the optimal pH and temperature for competence were 7.0 and 20C to 30C, respectively. The transformation of B. subtilis KPM 73 reached a maximum level after 20 min of exposure to DNA, B. subtilis BD 224 after 30min, and B. subtilis RM 125 after 10 min. Ca, Cu, Fe, Mg and Mn ions increased the transformation frequency of B. subtilis KPM 73 but Hg, Zn and Co ions decreased the transformation frequency. Ca ions were required for transformation of E. coli C600 and tranrsformation frequency was increased 20 times by addition of 75mM CaCl_2. The competence development of recipient cell was enhanced by addition of lysozyme in the competence medium and lysozyme was more affective in the early stage of competence development than the late stage of competence development, in which the spontaneous competence development reached maximum level. In sight of these observations, competence factor would seem to be a kind of cell wall lytic enzyme such as lysozyme. when the protoplasts of B. subtilis KPM 73 were transformed by terramycin resistance plasmid, the protoplasts were successfully transformed and the transformation frequency was 10^-2. The competent cells were treated with small amount of protein-digesting enzyme such as trypsin, and then exposed to transforming plasmid DNA. The recipient cells that were treated with trypsin were transformed 10 to 100 folds lower than non-trypsin-treated control cells. These results show that the binding factor must be a protein or at least a complex containing protein that is essential to it's activity. And external protein such as bovine albumin was effective on transformation of trypsin treated cell, suggesting that the cell surface-located binding factor did not have a specificity and the binding factor could be replaced by external substance such as bovine albumin. Terramycin resistance plasmid extracted from Ter^R transformant of B. subtilis KPM 73 was well transformed into B. subtilis KPM 73. And the electrophorsis pattern of Ter^R plasmid extracted from Ter^R transformant of B. subtilis KPM 73 was equal to that from St. rimosus.

炭化水素 資化細菌에 依한 amine의 酸化에 關한 硏究 : 第Ⅰ報 炭化水素 資化細菌의 分離 및 分離菌의 약간의 性質에 對하여 PartⅠIsolation and some psoperties of the hydrocarbon utilizing Bacteria

徐正塤 慶北大學校 1968 論文集 Vol.12 No.-

It is well known that many kinds of micro-organisms can utilize hydrocarbons as a sole carbon source. On the utilization of paraffin series of hydrocarbon, the oxidation is a first metabolic reaction. By this oxidation, the given hydrocarbon will be changed to a corresponding carboxylic acid. If this oxidation mechanism was introduced on the normal type of alkylmono-amine, the amine will be change to a ω-amino acid. The obtaining of a ω-amino acid is the object on this works. On the experiment, I have isolated 84 strains of micro-organisms from soil samples by the general culture techniques in a medium containing n-dodecan, n-hexane or n-propane and mineral salts. These isolated 84 strains of micro-organisms were inoculated in the amine containing mineral liquid medium and cultured by the shaking method for 2 or 3 weeks at 30℃. On this culturing condition, 57 strains of micro-organisms were found to have the ability of amine utilization. The subtracted amines was n-hexylamine, n-butylamine or isopropylamine as a sole carbon source.

화학 교육을 위한 개인용 컴퓨터 이용에 관한 연구

임정훈,이화국 全北大學校 科學敎育硏究所 1986 과학과 과학교육 논문지 Vol.11 No.-

The rapid developments of the computer technology in the eighties have enabled the wide use of computers for chemical education in school and universities. In Koreat however, computer uses in school and universities are in the primitive stage inspite of the relatively high computer hardware technology. In this study three related research tasks to promote computer use for chemical education in Korea were investigated by analyzing the CBE related experiences of the developed countries in general and examining the SERAPHIM projects and programs in particular. These three research tasks were: 1) the identification of possible computer uses for chemical education by comparing components of the chemical education system and functions of personal computers. 2) the survey of current status on the uses and developments of CBE systems by reviewing related literatures. 3) the formulation of ideas for the developments of the ideal coursewares and authoring systems by analyzing the current systems and strategies. Based on the above investigations some factual findings related with the three research tasks were given as conclusion of the study and several developmental projects and strategies to promote CBE in this country were provided as suggestions.

AN INHIBITORY SUBSTANCE PRODUCED FROM ASPERGILLUS SP. ON THE HEMORRHAGIC ACTIVITIES OF SNAKE VENOMS

Seu, Jung Hwn,Lee, Sun Young,Lee, Sang Hwa 경북대학교 유전공학연구소 1995 遺傳工學硏究所報 Vol.10 No.1

An antihemorrhagic substance (ISH) was obtained from a cultured broth of Aspergillus sp.. The ISH partially purified with ion exchange resins had very strong antihemorrhagic activity against snake venoms. In this studies, five kinds of hemotrhagic fractions obtained from the venom of Agkistrodon blomhoffii brevicaudus by DEAE-Sephadex chromatography and the hemorrhage due to Rhobdophis tigrinus tigrinus venom were strongly inactivated by ISH. Also, the lethal and hemorrhagic activities of HR-I fraction of Trimeresurus fiavoviridis venom were remarkably inhibited by ISH.

Pilot Scale 에서의 Fusant 의 Ethanol 발효

서정훈(Jung - Hwn Seu),김영호(Young - Ho Kim),이순모(Soon - Mo Lee),방병호(Byung - Ho Bang) 한국미생물생명공학회 1989 한국미생물·생명공학회지 Vol.17 No.1

Saccharomyces cerevisiae 의 Transformant 와 Candida tropicalis 간의 Intergteneric Protoplast Fusion

서정훈(Jung - Hwn Seu),전도연(Do - Youn Jun),김영호(Young - Ho Kim) 한국미생물생명공학회 1989 한국미생물·생명공학회지 Vol.17 No.1

STUDIES ON THE PROTEINASE AND HEMORRHAGIC FACTOR OF AGKISTRODON BLOMHOFFII BREVICAUDUS VENOM

Seu, Jung Hwn,KWON, GI SEOK 경북대학교 유전공학연구소 1995 遺傳工學硏究所報 Vol.10 No.1

A lyophilized venom of Agkistrodon blomhoffii brevicaudus was fractionated with DEAE-Sephadex A-50 and separated into eight different fractions. The proteinase activity was detected from all the fractions, but more than 40% of the activity was existed in both fraction of 6 and 8. And the proteinase representing the highest specific activity was existed in fraction 1. Proteinase activity contained in eight fractions were remarkably inhibited by the addition of same amount of ISV produced by a species of Penicillium. The inhibition ratio of ISV on the proteinase of fraction 3 was 100%, but that of fraction 2 was 72%, On the hemorrhagic activity, about 70% of the activity was detected in fraction 5 of which the proteinase showed the strongest specific activity compared with the other fraction. On the other hand, the edema activity was also distributed in the six fractions, however, about 45% of the activity was found in fraction 3. And this fraction showed the highest specific activity than any others.

Mini - jar fermentor Scale 에서의 Fusant 의 Ethanol 발효

서정훈(Jung - Hwn Seu),김영호(Young - Ho Kim) 한국미생물생명공학회 1989 한국미생물·생명공학회지 Vol.17 No.1

SYNTHESIS OF ALANYL^4-ISOLEUCYL^5-ANGIOTENSIN Ⅱ

Seu, Jung-Hwn,Robert R. Smeby,F. M. Bumpus 慶北大學校 1962 論文集 Vol.6 No.-

Resent studies on analogues and homologues of angiotensin I, the pressor octapeptide L-aspart1-L-arginyl-L-valyl-L-tyrosyl-L-histidyl-L-prolyl-L-phenylalanine, have shown the two amino acids with aomatic rings are important to biological activity. Removal of the aromatic ring of phenylalanine greatly reduced pressor activity. The peptide without the phenolic hydroxy group of tyrosine, phenylalanine angiotensin, has only 2 to 10% of the activity of the parent octapeptide. The two aromatic side gropes are positioned, very close to each other in a conformation recently suggested for angiotensin I.

Synthesis of Isoleucyl^5-Alanyl^7-Angiotensin Ⅱ

Seu, Jung-Hwn,Smeby, Rbert R.,Bumpus, F. Merlin 慶北大學校 1962 論文集 Vol.6 No.-

The octapeptide isoleucyl -alanyl -angiotensin Ⅱ has been synthesized in order to study further the significance of structure at the C-terminal end of angiotesin Ⅱ for biological activity. This replacement of proline, in position 7 of angiotensin Ⅱ, by alanine, greatly reduced the pressor and oxytocic activites of the peptide. This marked loss of activity, by merely removing two methylene groups of the proline ring, may be caused by a changing of the confermation at the C-terminus of the peptide. Addition of urea to an aqueous solution of angiotensin Ⅱ greatly reduces its myotrpohic action and also causes a marked reduction in degree of order showing bythe peptide as studied, by optical rotatory dispersion. From this it follows that the conformation of the peptide is an important factor for the myotrophic activity. Isoleucyl -angiotensin Ⅱ, the octapeptide L-aspartyl-L-arginyl-L-valyl-L_tyrosyl-L-isoleucyl-L-histidyl-L-prolyl-L-phenylalanine, exhibits marked specificty of structure at the C-terminus for pressor and myotrophic activities. Removal of L-phenylalanine or only the aromatic ring of this amino acid destroys the biological activities of the peptide. Conversion of the C-terminal carboxyl group to an amide group causes some reduction in biological activities. The phenolic ring of tyrosine and the imidazole ring of histidine have also been reported to be essential for the biological activities of the peptide. A conformation recently suggested for angiotensin Ⅱ , based on the assumption it will form anα-helix to the greatest extent possible, will explain all physical and biological data presently known for this peptide. In this conformation the groups essential for biological activity are all arranged in close proximity and on the same side of the molecule. Since rupture of the aliphatic ring of proline would change the stucture at the C-terminus of the peptide and would alter the relative position of these essential groups, we have replaced proline in angiotensin Ⅱ with alanine by the preparation of isoleucyl -ananyl angiotensin Ⅱ.