• Title/Summary/Keyword: Proteolysis System

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Effects of Glucose on Insulin-like Growth Factor Binding-5 Expression in Human Fibroblasts. (사람의 섬유아세포에서 Glucose 농도가 Insulin-like Growth Factor Binding Protein-5의 발현에 미치는 영향)

  • Ryu, Hye-Young;Hwang, Hye-Jung;Kim, In-Hye;Ryu, Hong-Soo;Nam, Taek-Jeong
    • Journal of Life Science
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    • v.17 no.9 s.89
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    • pp.1224-1231
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    • 2007
  • Insulin-like growth factor-I (IGF-I) and IGF-II have structure like insulin. In contrast to insulin, however, the bioavaility of IGFs is modulated by the IGF-binding protein (IGFBPs). Each of IGFBPs was different with molecular masses, biological characteristics, and immunological properties.. Human fibroblasts secrete IGFBPs that can modify IGF-I action. In diabetes mellitus, the most study of IGF systems have been investigated in insulin-dependent diabetes mellitus, non-insulin-dependent diabetes mellitus, and streptozotocin-in-duced animals in vivo. Recently, a little research regarding the IGFs system has been proposed in por-tion of cell in vitro. In this study, effects of low or high glucose condition on IGFBP-5 in GM10 was investigated. By western blotting analysis, IGFBP-5 level decreased in cells cultured at high glucose, but IGFBP-5 level of mRNA didn't change. IGFBP-5 protease that cleaves IGFBP-5 in conditioned me-dium had was inhibited by EDTA and heparin, like serine protease and metalloprotease. Furthermore, the protease activity was increased in high glucose cultivated condition. In results of gelatin zymog-raphy, molecular weight of proteolytic metalloenzymes was indentified 69-kDa and protease activity was increased in time-dependent manner. Although the mechanism has yet to be determined, IGFBP-5 proteolysis in GM10 cells cultured with high glucose may increase effects of IGFs to decrease the glu-cose level through dissociation of IGFs from IGFBPs. Therefore, we suggest that IGF- I and IGFBPs could be potential models in study of pathophysiology such as diabetes mellitus.

The Physicochemical Characteristics of Marinated Beef Galbi under Different Cooking Conditions (양념 소갈비의 조리과정에서의 물리화학적 특성 평가)

  • Hong, Sang-Pil;Kim, Young-Ho;Lee, Nam-Hyouck;Heo, Yeong-Uk
    • Journal of the Korean Society of Food Culture
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    • v.28 no.1
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    • pp.78-88
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    • 2013
  • Marinated beef galbi is a traditional Korean dish cooked with soy sauce, pear juice, onion, sesame oil, and sugar. However, there are many differences in beef galbi, including flavor and physicochemical aspects, depending on cooking conditions. Therefore, the physicochemical characteristics of marinated beef galbi prepared through various recipes was evaluated for its effects on pH, texture, aging, proteolysis, heating conditions, cooking time, and flavor compounds (pyrazines, IMPs, or FAAs). There were significant differences in salt concentration (0.8~3.03%), pH (4.89~6.22), and solid soluble contents (1.34-6.31 Brix) between recipes in this study. In the Pearson assay for sensory evaluation, overall preference correlated well with texture (a well-known sensory attribute in meat evaluation). Controlling the pH of meat through soaking in lemon solution, alkali water, phosphate, and baking powder solution, improved water holding capacity as much as 9 to 15% compared with the control. The myofibril index (MFI) of marinated meat stored at $4^{\circ}C$ increased 32% with 24 hours of aging and reached 39% at 48 hours of aging, and its fragmentation was observed through microscopy. SDS-PAGE showed hydrolysis of acid-soluble collagen by the pear juice, possibly related to meat tenderness. On the basis of surface temperature, the cooking time was estimated to be 8 minutes with pan heating at $170^{\circ}C$, 6 minutes at $270{\sim}300^{\circ}C$, and 4 minutes with charcoal at $700{\sim}900^{\circ}C$. Different pyrazine compounds, such as 2-methyl-3-phenylpyrrol(2,3-b) pyrazine (the typical product of the browning reaction) was mainly detected, and IMP (one of the main taste compounds in beef) was in higher amounts with the charcoal treatment, potentially related to its flavor preference among treatments. Our results demonstrate an effective case study and cooking system for beef galbi.

Endometrium from Women with Endometriosis Expresses Decreased Levels of Plasminogen Activator Inhibitor-1 and Tissue Inhibitor of Metalloproteinase-3 Compared to Normal Endometrium (자궁내막증 환자와 정상 여성의 자궁내막에서 TIMP-3와 PAI-1 mRNA 발현 차이에 관한 연구)

  • 정혜원
    • Development and Reproduction
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    • v.3 no.1
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    • pp.29-38
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    • 1999
  • The pathogenesis of endometriosis is unknown, but retrograde menstruation is widely accepted as an etiology. Refluxed endometrium from endometriosis patients is more prone to implant and invade peritoneum possibly through the action of extracellular proteolysis. This proteolytic action may involve plasminogen activators and the collagenase system. Plasminogen activators (PAs) and matrix metalloproteinases (MMPs) play a critical role in the breakdown of extracellular matrix components and basement membrane in the processes of implantation and tumor invasion. PAs are inhibited by plasminogen activator inhibitor (PAI) and MMPs activity is inhibited by tissue inhibitor of metalloproteinase (TIMP). To test the hypothesis that lower expression of PAI-1 and TIMP-3 in endometrium from women with endometriosis, we investigated their PAI-1 and TIMP-3 expression by quantitative competitive RT PCR in endometrium from women with and without endometriosis. Endometrial tissues were obtained from 14 patients with severe endometriosis and 14 patients without endometriosis. Total RNA was extracted and reverse transcribed into cDNA, and quantitative competitive PCR (QC PCR) was performed to evaluate PAI-1 and TIMP-3 mRNA expression. Endometrium from patients with endometriosis showed decreased expression of PAI-1 and TIMP-3 mRNA compared to endometrium from control in luteal phase (p<0.05). Our results suggest that endometrium from women with endometriosis expresses lower levels of PAI-1 and TIMP-3 than endometrium from normal women. Endometrium from endometriosis patients may be more invasive and prone to peritoneal implantation than control because of higher PA and MMP enzymatic activity. Thus, increased proteolytic activity may be one of the reasons for the invasive properties of the endometrium resulting in the development of endometriosis.

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Endogenous Phenoloxidase Purified from an Earthworm, Lumbricus rubellus (붉은 지렁이(Lumbricus rubellus) 체내로부터 정제한 Phenoloxidase)

  • 백승렬;조은정;유경희;김유삼;서정진;장정순
    • The Korean Journal of Zoology
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    • v.39 no.1
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    • pp.36-46
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    • 1996
  • An endogenous phenoloxidase (EPO) from earthworm, Lumbricus rubellus, has been purified and characterized. The purified EPO using ammonium sulfate fractionation, Blue-2, Phenyl-, and Q-sepharose chromatography steps was revealed in SDS-PAGE as a single protein banri with Mr. of 59 kl)a. A native strudure of the enzyme was examined with an in situ staining of a nondenatudng-PAGE using DL-dopa as a substrate. The result showed that a single band due to the EPO activity was located siighdy above a standard polypeptide with Mr. of 210 kl)a. These fads indicate that the EPO is an oligomeric enzyme. The presence of a monophenolase activity of the purified EPO, which hydroxylates tyrosine to dopa, was confirmed by observing dopachrome accumulation at 475 nm at PH 8.0 with a typical lag phase during 60 mm. of meausrement. A series of inhibition study has been performed for the enzyme with several divalent cation chelators such as phenyithiourea (Flu), 1, lO-phenanthroline, EDTA, and EGTA. Among them, only V'flj inhibited the enzyme with 1C0.5 of 65 MM, which indicated that copper was critical for the catalysis of EPO. The enzyme was maximally active at 35'C and pH 8.0 when L-dopa to dopachrome conversion was spectrophotometricaily monitored at 475 nm. The apparent Km values of P0 for L-opa were obtained as 1.86 mM and 13.8 mM at pH 6.5 and 8.0, respectively. The catalytic efficiencies at both pH were almost identical [(kat/Km)pH8.0/(kcat/Km)pH6.5 = O.92] while the Vmax at p11 8.0 was 6.6-fold higher than that at pH 6.5. This fact may indicate that pH affeds the catalysis at substrate and/or enzyme-substrate complex level rather than the enzyme itself. Taken together, the EPO was an oligomeric enzyme which did not require proteolysis for its activation. These results also indicated that the enzyme can exist, at least, in part as a latent form In vivo, which might be distinct from the prophenoloxidase activating system. Therefore, it is pertinent to consider that there must be certain regulatory molecules or phenomena in L. rubellus which make the 1,0 in a latent form in vivo before the foreign invasions.

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mRNA Expression Differences of uPA, uPAR in Eutopic Endometrium of Advanced Stage Endometriosis Patients (중증 자궁내막증 환자의 자궁내막과 정상인 자궁내막에서 uPA, uPAR mRNA 발현의 차이에 관한 연구)

  • Hur, Sung Eun;Lee, Ji Young;Lee, Woon Jung;Chung, Hye-Sung;Chung, Hye Won
    • Clinical and Experimental Reproductive Medicine
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    • v.33 no.4
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    • pp.229-236
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    • 2006
  • Objective: We investigated the expression of uPA and uPAR in eutopic endometrium of advanced stage endometriosis and control patients. Methods: The 33 endometriosis patients and 32 controls were enrolled. Endometrial samples were obtained from 65 premenopausal women aged 29-44 years, undergoing laparoscopic surgery or hysterectomy for non-malignant lesions. Sufficient samples were collected from 33 patients with endometriosis stage Ill and IV and 32 controls without endometriosis confirmed by laparoscopic surgery. The mRNA expression of uPA and uPAR from eutopic endometrium were analyzed by RT-QC PCR. Results: The mRNAs of uPA and uPAR were expressed in eutopic endometrium from endometriosis and normal controls throughout the menstrual cycle. Uterine endometrium from women with endometriosis expresses significantly (p<0.05) higher levels of u-PA mRNA than endometrium from normal women without endometriosis in the proliferative phase. There were no significant differences in expression of uPAR in eutopic endometrium between controls and endometriosis patients. Conclusion: These results suggest that eutopic endometrium from endometriosis patients may be more invasive and prone to peritoneal implantation because of greater u-PA mRNA expression than endometrium from women without endometriosis. Thus, increased proteolytic activity may be one etiology for the invasive properties of the endometrium resulting in the development of endometriosis.