• Title/Summary/Keyword: Membrane binding

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A Dipstick-Type Electrochemical Immunosensor for The Detection of The Organophosphorus Insecticide Fenthion

  • Cho, Young-Ae;Cha, Geun-Sig;Lee, Yong-Tae;Lee, Hye-Sung
    • Food Science and Biotechnology
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    • v.14 no.6
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    • pp.743-746
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    • 2005
  • A dipstick-type immunochemical biosensor for the detection of the organophosphorus insecticide fenthion was developed using a screen-printed electrode system as an amperometric transducer with polyclonal antibodies against fenthion as a bioreceptor. The assay of the biosensor involved competition between the pesticide in the sample and pesticide-glucose oxidase conjugate for binding to the antibody immobilized on the membrane. This was followed by measurement of the activity of the bound enzyme by the supply of the enzyme substrate (glucose) and amperometric determination of the enzyme reaction product ($H_2O_2$). The activity of the bound enzyme was inversely proportional to the concentration of pesticide. The optimized sensor system showed a linear response against the logarithm of the pesticide concentration ranging from $10^{-2}$ to $10^3\;{\mu}g/L$.

Quantitative Evaluation of Liver Function with Hepatic Receptor Scintigraphy using Tc-99m Galactosylated Serum Albumin (GSA) (Tc-99m Galactosylated Serum Albumin (GSA)을 이용한 정량적 간수용체 영상술)

  • Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.4
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    • pp.305-313
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    • 1998
  • The reduction in the amount of asialoglycoprotein (ASGP) receptor, which resides exclusively on the plasma membrane of functioning mammalian hepatocytes, as a consequence of hepato-cellular damage has been demonstrated in various pathologic conditions of the liver. Galac-tosylated human serum albumin (GSA) is a newly developed receptor-binding agent, specific for the ASGP receptor. Tc-99m GSA binds quantitatively to liver ASGP receptors and the rate of accumulation in the liver is dependent on hepatic function represented as the amount of receptor, as well as the amount of ligand injected, its affinity to the receptor and the hepatic blood flow. The findings of Tc-99m GSA scintigraphy were reported to reflect the hepatic function of the patients with large hepatic tumors, obstructive jaundice, acute and chronic liver disease. Tc-99m GSA scintigraphy is an easy and reliable test and has the clinical potentials to evaluate the liver function in the patients with hepatic disorders.

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Affinity labeling of the Vacuolar Arginine Transporter in Neurospora crassa (Neurospora crassa의 액포에 존재하는 arginine transporter의 표지방법)

  • ;Weiss, R. L.
    • Korean Journal of Microbiology
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    • v.27 no.2
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    • pp.108-116
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    • 1989
  • Based on the specificty of recognition of the vacuolar arginine transporter, N-p-nitrobenzoxycarbonyl (NBZ)-L-arginyl diazomethane was synthesized and used as an affinity label specific for the arginine transporter. This arginyl derivative ingibited both ATP-dependent and independent L-arginine transport into vacuolar membrane vesicles. When vacuolar proteins were labeled with radioactive NBZ arginyl diazomethane, the binding was irreversible, detached by treatment with base and blocked by treatment with cysteinyl blocking groups suggesting cysteine as a labeling site.

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Molecular cloning and characterization of Izumo1 gene from bovine testis

  • Kim, Ekyune
    • Journal of Animal Science and Technology
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    • v.57 no.4
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    • pp.16.1-16.7
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    • 2015
  • A well-characterized sperm specific protein of the Member of immunoglobulin superfamily, IZUMO1, has crucial role in fertilization by mediating sperm binding to the egg plasma membrane in the mouse. However little is known about IZUMO1 in bovine. Here, we describe the molecular cloning and expression analysis of bovine IZUMO1 (bIZUMO1). RT-PCR and Western blot analysis of the bovine tissues indicated that bIZUMO1 was specifically expressed in the testis and sperm, Furthermore, the result of our biotinylation assay from ejaculated bovine sperm strongly suggest the assumption that bIZUMO1 is localized on the cell surface. These data imply the potential role of bovine IZUMO1 in mammalian fertilization.

Molecular and Functional Characterization of Mouse Cardiac Junctate

  • Hong, Chang-Soo;Cho, Myeong-Chan;Kwak, Yong-Geun;Chae, Soo-Wan;Kim, Do-Han
    • Proceedings of the Korean Biophysical Society Conference
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    • 2002.06b
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    • pp.57-57
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    • 2002
  • Junctate is a newly identified integral endo(sarco)plasmic reticulum membrane calcium binding protein, which is an alternative splicing form of the same gene generating aspartyl-hydroxylase and junctin. Screening a mouse heart cDNA library using canine junctin cDNA as a probe yielded 3 complete mouse heart cDNAs.(omitted)

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Immunological Studies on the Surface Antigens of Tumor Cell (II) Introduction to Immunological Studies on the Development and Cell Differentiation of the Leukemia Cell (종양세포 표면항원에 대한 분자면역학적 연구(II) 백혈병세포의 발생과 세포분화에 관한 연구)

  • 김한도;김정락박병채
    • The Korean Journal of Zoology
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    • v.34 no.4
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    • pp.469-478
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    • 1991
  • The CALLA on the surface of leukemic cell lines, recognized by our monoclonal antibody. KP-22(IgG1, K) was one of cell surface glycoproteins having moi. wt. of approximately 100,000 dalton, and could be shed in spent medium or endocytosed when binding the cognate antidoby, KP-22. In the presence of cognate antibodies, 60% of CALLAS recogniEed by KP-22 MAs were modulated and cleared from the cell surface during 24 hrs, and approximaetely 35% of them was endocytosed and 25%, was shed in spent medium. The reappearance of the membrane CALLA after modulation by the KP-22 required at least 6 hours and supposed to be newly synthesized molecules.

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Insulin Delivery Systems: Current Topic

  • Jeong, Seo-Young
    • Journal of Pharmaceutical Investigation
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    • v.16 no.3
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    • pp.89-100
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    • 1986
  • Although insulin has been available for the treatment of diabetes mellitus for more than half a centry, the deficiency of conventional insulin therapy for diabetic patients have, to this date, not been satisfactorily overcome by any method. The development of potential delivery systems for insulin is highly important to prevent excessive fluctuation of plasma glucose levels, which results in long term complications in the diabetic. There are three major approaches toward development of glucose responding insulin delivery systems: A bioengineering approach is to devise mechanical components capable of releasing insulin in amounts appropriate to varying blood-glucose requirements. A biological approach relies upon cultured, living pancreatic beta cells encapsulated to constitute an insulin delivery unit. A biochemical approach is to synthesize a stable and biologically active glycosylated insulin that is complementary to the binding sites of lectin. This paper will cover several specific areas, including pancreatic transplantation(total or isolated islet cells), artificial pancreases(bioengineering or biological approach), controlled delivery system, glucose sensitive membrane systems, and a self-regulating insulin delivery system.

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Investigation of Binding Modes of the Verapamil and Curcumin into Human P-glycoprotein (P-gp)

  • Gadhe, Changdev G.;Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.6 no.4
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    • pp.205-210
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    • 2013
  • Human P-gp is a protein responsible for the multidrug resistance (MDR) and causes failure of cancer chemotherapy. Till date no X-ray crystal structure is reported for this membrane protein, which hampers active research in the field. We performed homology modeling to develop three dimensional (3D) model of P-gp, and docking studies of the verapamil and curcumin have been performed to gain insight into the interaction mechanism between inhibitors and P-gp. It was identified that the inhibitors docked into the upper part of P-gp and interacted through the hydrophobic interactions.

Role of Protein Kinase C in $\alpha_1$-Adrenergic Regulation of $a^i_{Na}$ in Single Guinea Pig Ventricular Myocyles

  • Jo, Su-Hyun;Lee, Chin-Ok
    • Proceedings of the Korean Biophysical Society Conference
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    • 1997.07a
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    • pp.28-28
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    • 1997
  • Stimulation of $\alpha$$_1$-adrenergic receptor ($\alpha$$_1$-AR) by phenylephrine produced a decrease in intracellular N $a^{+}$ activity ( $a_{Na}$ $^{i}$ ) in multicellular preparations of cardiac tissues. The role of protein kinase C (PKC) in $\alpha$$_1$-adrenergic regulation of $a_{Na}$ $^{i}$ was studied in single ventricular myocyte isolated from guinea pig hearts. $a_{Na}$ $^{i}$ and membrane potential were measured with N $a^{+}$ indicator, sodium-binding benzofuran isophthalate tetraacetoxy methyl ester (SBFI/AM) and microelectrodes respectively when ventricular myocyte was stimulated at 0.3 Hz.(omitted)d)

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