• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1998 Fiscal Year Final Research Report Summary

Structure and Enzymatic Activity of an Intramolecular Complex of Enzyme with Polyelectrolyte

Research Project

Project/Area Number 08455434
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 高分子合成
Research InstitutionUniversity of Tsukuba

Principal Investigator

KOKUFUTA Etsuo  Institute of Applied Biochemostry, University of Tsukuba Professor, 応用生物化学系, 教授 (40124648)

Co-Investigator(Kenkyū-buntansha) HIRATA Mitsuo  Department of Industrial Chemistry, Nihon University, Professor, 生産工学部, 教授 (00059768)
Project Period (FY) 1996 – 1998
Keywordsprotein / polyelectrolyte / water-solube polymer / poly (ethylene glycol) / laser-light scattering / electrophoretic light scattering / complex formation mechanism / intrapolymer complex
Research Abstract

Complexation of proteins with polyelectrolytes is interesting from two points of view. The first concerns the way in which the polymers interact with non-flexible protein molecules. The second concerns the extent to which biochemical activity is maintained in the resulting complexes, the answer to which is central to the molecular design of composite protein-polymer systems, such as immobilized enzymes, as well as to the design of protein separation processes using water-soluble polymers.
By combinations of quasi-elastic light scattering (QELS), static light scattering (SLS), electrophoretic light scattering (ELS) techniques, we suggested that polyion and protein give forth an "intrapolymer" complex at a low ionic strength. However, such complexes readily aggregate ; therefore, many difficulties arise in the characterization of intrapolymer complex.
Complexes of proteins with neutral polymers are less prone to exhibit such aggregation effects ; thus, the complexation between human serum albumin (HSA) and poly(ethylene glycol) (PEG) was studied. QELS study for aqueous HSA-PEG mixtures at different levels of pH and ionic strength (NaCI) showed the formation of a water-soluble complex, the size of which varied depending on both ionic strength and molecular weight of PEG but remained unaltered when the mixing ratio of PEG to HSA was varied. The study of the complexation in the presence and absence of 1M urea as a function of pH by QELS and fluorescence spectroscopy showed that hydrogen bonding plays an important role in the complex formation. A combination of SLS and dialysis method at pH 2 and at ionic-strength of 0.1 demonstrated that the complexation yields an intrapolymer complex in which several HSA molecules bound to a PEG chain. In addition, ELS indicated that the resulting intrapolymer complex behaves like a free draining coil during electrophoresis.

  • Research Products

    (6 results)

All Other

All Publications (6 results)

  • [Publications] J.Xia,P.L.Dubin,T.Izumi,M.Hirata,E.Kokufuta: "Dynamic and Electrophoretic Light Scattering of Poly (dimethyldiallylammonium chloride) in Salt-free Solutions" j.polym.Sci.,Polym Phys.Edn.Part B,Polymer Physics. 34[3]. 497-503 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A.Tsuboi,T.Izumi,M.Hirata,J.Xia,P.L.Dubin,E.Kokufuta: "Complexation of Proteins with a Strong Polyanion in an Aqueous Salt-free System" Langmuir. 12[26]. 6295-6303 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S.Azegami,A.Tsuboi,T.Izumi,M.Hirata,P.L.Dubin,B.Wang,E.Kokufuta: "Formation of an Intrapolymer Complex from Human Serum Albumin and Poly (Ethylene Glycol)" Langmuir. 15[4]. 940-947 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] J.Xia, P.L.Dubin, T.Izumi, M.Hirata, E.Kokufuta: "Dynamic and Electrophoretic Light Scattering of Poly (dimethyldiallylammonium chloride) in Salt-free Solutions" J.Polym.Sci., Polym Phys.Edn.Part B,Polymer Physics. 34 [3]. 497-503 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Tsuboi, T.Izumi, M.Hirata, J.Xia, P.L.Dubin, E.Kokufuta: "Complexation of Proteins with a Strong Polyanion in an Aqueous Salt-free System" Langmuir. 12 [26]. 6295-6303 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] S.Azegami, A.Tsuboi, T.Izumi, M.Hirata, P.L.Dubin, B,Wang, E.Kokufuta: "Formation of an Intrapolymer Complex from Human Serum Albumin and Poly (Ethylene Glycol)" Langmuir. 15 [4]. 940-947 (1999)

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 1999-12-08  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi