• Title/Summary/Keyword: proteolysis

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Doxorubicin Binds to Un-phosphorylated Form of hNopp140 and Reduces Protein Kinase CK2-Dependent Phosphorylation of hNopp140

  • Kim, Yun-Kyoung;Lee, Won-Kyu;Jin, Young-nam;Lee, Kong-Joo;Jeon, Hye-sung;Yu, Yeon-Gyu
    • BMB Reports
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    • v.39 no.6
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    • pp.774-781
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    • 2006
  • Human nucleolar phosphoprotein p140 (hNopp140) is a nucleolar phosphoprotein that can bind to doxorubicin, an anti-cancer agent. We have examined the interaction between hNopp140 and doxorubicin as well as the folding property of hNopp140. Also, the effects of ATP and phosphorylation on the affinity of hNopp140 to doxorubicin are investigated by affinity dependent co-precipitation and surface plasmon resonance methods. Doxorubicin preferentially binds to un-phosphorylated form of hNopp140 with a $K_D$ value of $3.3\;{\times}\;10^{-7}$ M. Furthermore, doxorubicin reduces the protein kinase CK2-dependent phosphorylation of hNopp140, indicating that doxorubicin may perturb the cellular function of hNopp140 by reducing the protein kinase CK2-dependent phosphorylation of hNopp140. Low contents of the secondary structures of hNopp140 and the fast rate of proteolysis imply that hNopp140 has a high percentage of flexible regions or extended loop structures.

Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity of Elk (Cervus elaphus) Velvet Antler

  • Karawita Rohan;Park, Pyo-Jam;Siriwardhana Nalin;Jeon, Byong-Tae;Moon, Sang-Ho;Ahn, Duk-Kyun;Chos, Somi-K.;Jeon, You-Jin
    • Preventive Nutrition and Food Science
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    • v.10 no.3
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    • pp.239-243
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    • 2005
  • Angiotensin I-converting enzyme (ACE) inhibitory activities of elk antler hydrolysates prepared with three kinds of proteases, pepsin, trypsin and $\alpha-chymotrypsin$, were investigated. The ACE inhibitory activity of the pepsinolytic hydrolysate was the highest with an $IC_{50}$ value of $9.3\mu g/mL.$ In addition, three kinds of pepsinolytic hydrolysates with relatively high molecular weights (over 10,000 Da), medium molecular weights (5,000 to 10,000 Da), and low molecular weights (below 5,000 Da) were fractionated using an ultrafiltration membrane system. The below 5,000 Da hydrolysate exhibited the highest ACE inhibitory activity. These results indicate that the pepsinolytic hydrolysates of elk velvet antler could be a good source of peptides with ACE inhibitory activity.

Assimilation of Peptides and Amino Acids and Dissimilation of Lactate During Submerged Pure Cultures of Penicillium camembertii and Geotrichum candidum

  • Aziza, M.;Adour, L.;Amrane, A.
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.124-127
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    • 2008
  • The behavior of Penicillium camembertii and Geotrichum candidum growing in submerged pure cultures on simple (glutamate) or complex (peptones) substrates as nitrogen and carbon sources and lactate as a second carbon source was examined. Similar to the behavior previously recorded on a simple substrate (glutamate), a clear differentiation between the carbon source and the energy source was also shown on peptones and lactate during P. camembertii growth, since throughout growth, lactate was only dissimilated, viz., used for energy supply by oxidation into $CO_2$, whereas peptides and amino acids from peptones were used for carbon (and nitrogen) assimilation. Because of its deaminating activity, G candidum preferred peptides and amino acids to lactate as energy sources, in addition to being assimilated as carbon and nitrogen sources. From this, on peptones and lactate, G candidum grew faster than P. camembertii (0.19 and 0.08 g/l/h, respectively) by assimilating the most readily utilizable peptides and amino acids; however, owing to its lower proteolytic activity, the maximum biomass was lower than that of P. camembertii (3.7 and 5.5 g/l, respectively), for which continuous proteolysis and assimilation of peptides were shown.

Protein Cyclization Enhanced Thermostability and Exopeptidase-Resistance of Green Fluorescent Protein

  • Zhao, Zhonglin;Ma, Xin;Li, Liang;Zhang, Wei;Ping, Shuzhen;Xu, Ming-Qun;Lin, Min
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.460-466
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    • 2010
  • A mutant of green fluorescent protein ($GFPmut3^*$) from the jellyfish Aequorea victoria was cyclized in vitro and in vivo by the use of a naturally split intein from the dnaE gene of Synechocystis species PCC6803 (Ssp). Cyclization of $GFPmut3^*$ was confirmed by amino acid sequencing and resulted in an increased electrophoretic mobility compared with the linear $GFPmut3^*$. The circular $GFPmut3^*$ was $5^{\circ}C$ more thermostable than the linear form and significantly more resistant to proteolysis of exopeptidase. The circular $GFPmut3^*$ also displayed increased relative fluorescence intensity. In addition, chemical stability of $GFPmut3^*$ against GdnHCl revealed more stability of the circular form compared with the linear form.

Development of Modified Phenylalanine Ammonia-lyase for the Treatment of Phenylketonuria

  • Kim, Woo-Mi
    • Biomolecules & Therapeutics
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    • v.17 no.1
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    • pp.104-110
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    • 2009
  • Phenylketonuria (PKU) is an inherited metabolic disorder caused by mutations in the phenylalanine catabolic enzyme, phenylalanine hydroxylase (PAH). The use of phenylalanine ammonia-lase (PAL) by oral and parenteral routes as a therapeutic drug for PKU has been severely limited due to inactivation by intestinal proteolysis and immune reactions. PEGylation was applied to PAL to reduce the degrees of antigenicity and proteolytic inactivation. Kinetic experiments with native PAL and pegylated PALs were performed, and pH stability, temperature stability, and protease susceptibility were evaluated. Enzyme linked immunosorbent assay (ELISA) was carried out to measure the immune complex between pegylated PALs and antiserum that had been extracted from a PAL-immunized mouse. Pegylated PAL, especially branched pegylated PAL (10 kDa, 1:32), was more active for phenylalanine and more stable in pancreatic proteases than native PAL. Native PAL was optimal at pH 8.5, corresponding to the average pH range of the small intestine; the same finding was noted for pegylated PALs. All linear and branched pegylated PALs had low reactivity with mouse antiserum, especially the 1:16 formulation with linear 5-kDa PEG and the 1:32 formulation with branched 10-kDa PEG. Therefore, we suggest the 1:32 formulation with branched 10-kDa PEG as the most promising formulation for enzyme replacement therapy.

Association of PAI-1 Polymorphism with Schizophrenia in Korean Population

  • Yoon, Seo-Hyun;Park, Hae-Jeong;Zheng, Longtai;Hong, Mee-Suk;Kim, Jong-Woo;Yim, Sung-Vin;Chung, Joo-Ho
    • Molecular & Cellular Toxicology
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    • v.2 no.3
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    • pp.212-215
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    • 2006
  • Several reports have suggested a possible relationship between blood coagulation factors and schizophrenia. Plasminogen activator inhibitor type 1 (PAI-1) belongs to a serine protease inhibitor family, which regulates fibrinolysis and proteolysis by inhibiting plasminogen activation. The purpose of this study was to investigate the association of polymorphisms of the PAI-1 gene with schizophrenia in Korean population. Two important polymorphisms (-675 4G/5G and -844 G/A) located on promoter region of the PAI-1 gene were analyzed on 178 schizophrenia patients and 226 controls. The genotypic and allelic associations of -675 4G/5G were found significant. Furthermore, haplotype analysis revealed significant result, which suggests that -675 4G/5G polymorphism might confer increased susceptibility for schizophrenia in Korean population.

식육의 연화증진에 관한 최근의 연구동향 - 적색육의 연도 증진에 이용되는 전기자극의 작용 -

  • 황인호
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2002.05a
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    • pp.17-25
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    • 2002
  • Application of electrical stimulation in the red meat species (eg. beef and sheep) processing has been erratic around the world and this may reflect an incomplete knowledge of how to optimise the technology. Although it is well established that stimulation increases the rate of post-mortem glycolysis other biochemical and biophysical effects have been implicated with the use of this technology. On the basis of currently available knowledge, this mini-review seeks to examine the current theories about the effect of stimulation on post-mortem muscle. The classical view that stimulation prevents muscle from shortening excessively during rigor development has been expanded to include the possibility that it also results in physical disruption of muscle structure. The interaction of these effects with the acceleration of the rate of proteolysis through activation of the calpain protease system has not been comprehensively reviewed in the past. As a result of conclusion driven, this article highlights several areas that may prove fruitful for further research. The challenge for further development of electrical stimulation systems is optimisation of the activation of the enzyme systems in parallel with manipulation of chilling regimes so as to ensure rigor mortis is achieved at temperatures which minimise shortening. The potential of regional stimulation of sections of the carcass to achieve this outcome is worthy of study given the different fibre composition of muscles and temperature gradients.

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A Potent Inhibitor of Pancreatic Serine Proteases from Chick Skeletal Muscle (계 골격근에서 순수분리한 Serine Protease Inhibitor의 특성과 작용기구)

  • 김옥매;정성수;박혜경;최준호;정진하;하두봉
    • The Korean Journal of Zoology
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    • v.33 no.1
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    • pp.119-125
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    • 1990
  • A Potent inhibitor of trypsin and other various serine proteases including chymotrypsin, elastase, kallikrein, plasmin and subtilisin, has been purified to homogeneity from chick skeletal muscle by convendonal chromatographic procedures. The Inhibitor has an apparent molecular weight of 66, 000 dalton as determined by gel filtration. When the purified inhibitor was electrophoresed in the presence of sodium dodecyl sulfate, there appeared rwo protein bands having molecular weights of 66, 000 and 64, 000 dalton. The 64, 000 dalton protein seems to be the product of 66, 000 dalton protein by a lin'ited proteolysis during the purification procedure or in viuo. Thus, it seems to consist of a single polypeptide. The inhibitor appeared to be glycoprotein and have an isoelectric point of 7.4. It contains relatively large amount (8.33 mole%) of cysteine residues.

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The Mechanisms by Which Electrical Stimulation Affect Meat Tendrness (전기 자극의 연도증진 기작에 관한 연구동향)

  • 황인호;박범영
    • Food Science of Animal Resources
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    • v.22 no.3
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    • pp.234-239
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    • 2002
  • The use of electrical stimulation in the red meat processing has been inconsistent and the mechanism(s) associated with the improvement of meat quality in electrically stimulated carcass has been disputed. This may reflect an incomplete knowledge of how to optimise the technology and also mirrors the existence of unknown factors. Although it is well established that the stimulation treatment increases the rate of post-mortem glycolysis, other biochemical and biophysical effects have been implicated with the use of this technology. The classical view that stimulation prevents muscle from shortening excessively during rigor development has been expanded to include the possibility that it also results in physical disruption of muscle structure and early 'turn-on' of tenderizing process. However, the interaction of these effects with the acceleration of the rate of proteolysis through activation of the calpain pretense system has not been comprehensively unravelled. This mini-review attempts to examine the current theories about the effect of stimulation on post-mortem muscle.

Postmortem Aging of Beef with a Special Reference to the Dry Aging

  • Khan, Muhammad I.;Jung, Samooel;Nam, Ki Chang;Jo, Cheorun
    • Food Science of Animal Resources
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    • v.36 no.2
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    • pp.159-169
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    • 2016
  • Animal muscles are stored for specific period (aging) at refrigerated temperatures, during and after which the living muscles start to convert into meat and thus, attain certain superior properties in the final product. Proteolysis, lipolysis, and oxidation are the major biochemical processes involved during the postmortem aging of meat that affect the tenderness, juiciness, and flavor, as well as sometimes may introduce certain undesirable traits. This review analyzes the role of pre- and post-mortem factors that are important for aging and their effect on the chemical and physical changes in the “dry- and wet-aged meat.” Thus, if the meat processing manufacturers optimize the effects of aging for specific muscles, the palatability, color, and the shelf life of the aged meat products could be significantly enhanced.