• Applied Biological Chemistry
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• 제34권4호
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• pp.334-338
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• 1991

고상법으로 새로운 반응기구에 의한 bradykinin 및 $(D-Phe7\;-Leu^8)$ bradykinin을 합성하였다. Coupling은 N, N'-dicyclohexylcarbodiimide로 행하였으며 HBr 용액으로 cleavage한 후 조펩티드는 high pressure liquid chromatography로 정제하였다. 이들 펩티드의 순도는 paper chromatography, thin layer chromatography, paper electrophoresis, 융점측정기 및 아미노산기분석기에 의하여 분석하였다. Endopeptidase인 ${\alpha}-chymotrypsin$과 trysin, exopeptidase인 carboxypeptidase A와 leucine aminopeptidase를 사용하여 in vitro 상에서 이들 펩티드의 분해실험을 하였다. ${\alpha}-Chymotrypsine$ 및 carboxypeptidase A에 의하여 이들 펩티드는 빠르게 분해하였으나 leucine aminopeptidase는 N-말단의 2번 위치에 proline의 imino결합 때문에 분해하지 않았다.

• Journal of Microbiology and Biotechnology
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• 제10권5호
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• pp.573-579
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• 2000

Knowledge on the enzymes acting on p-amino-acid-containing peptides appears to be somewhat limited when compared with those acting on peptides composed on L-amino acids. Less than ten D-stereospecific enzymes are hitherto known. This review describes about several novel D-stereospecific peptidases and amidases of microbial origin, including D-aminopeptidase (E.C. 3.4.11.19), alkaline D-peptidase, and D-amino aicd amidase, which are applied to the synthesis of D-amino acid/or D-amino acid derivatives.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.773-779
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• 2002

A gene (hap) encoding aminopeptidase from the chromosomal DNA of Bacillus licheniformis was cloned. The gene is 1,347 bp long and encodes a 449 amino acid preproprotein with a major mature region of 401 amino acids (calculated molecular mass 43,241 Da). N-Terminal sequence of the purified protein revealed a potential presence of N-terminal propeptide. The deduced primary amino acid sequence and the mass analysis of the purified protein suggested that a C-terminal peptide YSSVAQ was also cleaved off by a possible endogeneous protease. Tho amino acid sequence displayed 58% identity with that of the aminopeptidase from alkaliphilic Bacillus halodurans. This bacterial enzyme was overexpressed in recombinant Escherichia coli and Bacillus subtilis cells. Clones containing the intact hap gene, including its own promoter and signal sequence, gave rise to the synthesis of extracellular and thrmostable enzyme by B. subtilis transformants. The secreted protein exhibited the same biochemical properties and the similar apparent molecular mass as the B. lichenzyormis original enzyme.

• BMB Reports
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• 제45권6호
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• pp.360-364
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• 2012

Uptake of circulating glucose into the cells happens via the insulin-mediated signalling pathway, which translocates the glucose transporter 4 (GLUT4) vesicles from the intracellular compartment to the plasma membrane. Rab GTPases are involved in this vesicle trafficking, where Rab GTPases-activating proteins (RabGAP) enhance the GTP to GDP hydrolysis. TBC1D4 (AS160) and TBC1D1 are functional RabGAPs in the adipocytes and the skeletonal myocytes, respectively. These proteins contain two phosphotyrosine-binding domains (PTBs) at the amino-terminus of the catalytic RabGAP domain. The second PTB has been shown to interact with the cytoplasmic region of the insulin-regulated aminopeptidase (IRAP) of the GLUT4 vesicle. In this study, we quantitatively measured the ${\sim}{\mu}M$ affinity ($K_D$) between TBC1D4 PTB and IRAP using isothermal titration calorimetry, and further showed that IRAP residues 1-49 are the major region mediating this interaction. We also demonstrated that the IRAP residues 1-15 are necessary but not sufficient for the PTB interaction.

• Journal of Microbiology and Biotechnology
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• 제5권3호
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• pp.158-162
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• 1995

The effect of carbon and nitrogen sources on the production of novel aminopeptidase M inhibitors MR-387A and B by Streptomyces sp. SL-387 has been studied. High D-glucose and ammonia concentrations (5$\%$ and 1$\%$, respectively) exerted a negative influence on the inhibitor formation. The suppressive effect of glucose on the inhibitor formation is probably caused by an effect of medium pH rather than that of cyclic AMP. To establish the optimum conditions for inhibitor overproduction, various nitrogen sources and ammonium ion-trapping agents were examined. The use of ammonia slow-releasing nitrogen sources such as soybean meal and fish meal, or ammonium ion-trapping agents such as kaoline, celite, and natural zeolite achieved the enhancement of inhibitor production. These results also indicate that inhibitor formation is affected by ammonium ion repression.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.530-536
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• 2009

Cobalt chloride ($CoCl_2$) treatment of cells in vitro has been shown to induce cellular changes that are similar to those seen following hypoxia. To identify genes that are differentially expressed in response to treatment with $CoCl_2$, we compared the mRNA expression profiles of PC-3 cells that were treated with $CoCl_2$ with those of untreated PC-3 cells, using specific arbitrary primers and two anchored oligo(dT) primers provided in the ACP-based GeneFishing kits. The results of this study demonstrated that the puromycin-sensitive aminopeptidase (PSA) gene was down regulated in PC-3 cells that were treated with $CoCl_2$. This downregulation of PSA expression, in turn, suppressed the proliferation, migration, and invasion of PC-3 cells, as well as the secretion and expression of matrix metalloproteinase-9 (MMP-9).

• Toxicological Research
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• 제12권2호
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• pp.277-281
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• 1996

To evaluate the renal toxicity of the antitumor agent, 5-(piperidonomethylphenyl)-2,3-dihydroimidazo[2,1-a]isoquinoline (SDZ-62-434), rats were treated with SDZ-62-434 of 50 mg/Kg, i.p., once and 10 mg/Kg, i.p., daily for 7 days. The kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine, protein, and the activities of N-acetyl-$\beta $D-glucosaminidase (NAG), alanine aminopeptidase (AAP), $\gamma$-glutamyl transpeptidase (GGT) and lactate dehydrogenase (LDH) in 24 hr urine were also determined. The kidney weights after acute and subacute administration was not affected. The urine excretions were increased 5 days after the acute administration and increased after the daily 3rd day-administration. The excretion of creatinine was similar as that of urine excretion. The excretion of creatinine was increased 5 days after the acute and subacute administration. However, the protein excretion didn't changed in both treatment. Those indicate that SDZ-62-434 might induce the diuresis and also suggest that diuresis might be due to the some metabolites rather than the compound itself. The urinary activities of NAG and LDH were not affected after the acute treatment. However, the urinary activities of AAP and GGT were slightly increased 3 days after the acute administration but, returned to the control value. In subacute treatment, the activities of GGT was not changed. And the activities of NAG were declined after the 7th day-administration. However, the activities of AAP were significantly increased after the 5th day-administration. Furthermore, the urinary activities of LDH were continuously increased during the subacute administration. These results indicate that the high and subacute administration might induce a weak damage on the kidney cells. Furtherrnore, the present results suggest that SDZ-62-434 might have relatively slow-emerging and mild toxicity to the kidney.

• Journal of Plant Biology
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• 제37권3호
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• pp.357-363
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• 1994

An expreiment with non-nodulating alfalfa (Medicago sativa L.) plants was designed to investigate the changes in protein contents and the activities of proteolytic enzymes during a regrowth period of 24 d. Shoot removal caused a depression of root growth and significantly reduced protein contents in roots. An initial decline of root proteins for the first 10 d was followed by a rapid recovery from d 11 to 24. The major increase of regrowing shoot weight occurred also from d 11. The activities of aminopeptidase and endoprotease slightly decreased in regrowing leaves, while protein contents remains stable after shoot removal. Roots exhibited source behaviour with a rapid increase of endoprotease activities for the first 10 d of regrowth; about a 370% increase over the initial level was observed. Increase in endoprotease activity in roots coincided with the time of protein remobilization after shoot removal, indicating the important role of endoproteases in protein degradation.

• Toxicological Research
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• 제14권3호
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• pp.365-370
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• 1998

To evaluate the renal toxicity of the antitumor agent, p-{N,N,-Bis(2-chloroethyl)amino}-4-phenyl acetyl-amino-2,6-piperidinedione(CK-15), rats were treated with CK-15 (acute: 50mg/kg. i.p., single and subacute: 5mg/kg, i.p., daily for 7 days). The changes in the body weight, water consumption, kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine and portein, the activities of N-acetyl-${\beta}$-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) and lactate dehydrogenase (LDH) in 24hr urine were also determined. The body weight, water consumption, and urine volume were decreased after the acute and subacute administration. However the weights of kidney were not changed after the treatments. The excretion of creatinine was significantly decreased 1 day after acute administration but, returned to the control value. In subactute administration, the excretion of creatinine was gradually decreased. However, the protein excretion did not changed in both treatment. Those indicate that CK-15 might decrease the metabolic rate of muscle. THe urinary activities of NAG, AAP, ${\gamma}$-GT, and LDH were significantly affected bythe drug treatment. The urinary activities of NAG, AAP and ${\gamma}$-GT were significantly increased 1 day after the acute administration and then returned to the control value. However, the urinary activities of LDH were not changed in acute treatment. In subacute treatment, although the urinary activities of NAG were not changed, those of AAP and ${\gamma}$-GT were significantly increased 2.3 times at 3 days during the subacute administration. Also the urinary activities of LDH were significantly increased at 7 day after the administration. These results indicate that the high and subacute administration might induce a damage in the kidney cells. Furthermore the present results suggest that the toxic effects of CK-15 might be due to the accumulation of the metabolites.

• 미생물학회지
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• 제31권1호
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• pp.93-98
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• 1993

수계생태계에서 유기물질의 순환을 이해하기 위하여 팔당호에서 종속영양 활성도와 세균세포의 효소활성의 계절절 변화를 연구하였다. 팔당호 I 의 glucose 전환시간은 수층, 퇴적토에서 2-1,300 시간, 17-170 시간, protein hydrolysate 는 5-900 시간, 15-240 시간, acetic acid 는 4-350 시간, 15-230 시간으로 계절적인 변화를 나타냈다. Glucose, protein hydrolysate, acetate 각각의 호흡율은 수층에서 23-32%, 38-41%, 22-28%로 나타났고 퇴적토에서는 34%, 61% and 41% 로 나타났다. 이 결과로 3가지 유기물질 종류 모두가 수층보다 퇴적토에서는 높은 율로 호흡됨을 알 수 있었다. 한편 세균의 $\alpha$-glucosidase, $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase, aminopeptidase 활성력을 살펴본 결과 수층에서는 효소 각각에 대해 32-44%, 31-32%, 18-34% 61-67% 의 범위를 나타내었고 퇴적토에서는 34%, 40%, 23% 65%로 나타났다.