20S proteasome from LMP7 knock out mice reveals altered proteolytic activities and cleavage site preferences

FEBS Letters

Kloetzel, P.-M.²  Stohwasser, R.²  Kostka, S.¹  Kraft, R.¹  Kuckelkorn, U.² 

[1]Max Delbrück Centrum für Molekulare Medizin, Robert-Rössle Str. 10, D-13122 Berlin-Buch, Germany

[2]Institut für Biochemie der Charité, Humboldt Universität, Berlin, Hessische Str. 3-4, D-10115 Berlin, Germany

关键词: 20S Proteasome;    LMP7 knock out mouse;    Subunit MB1 peptidase activity;    HPLC;    high performance liquid chromatography;    MCA;    7-amido-4-methylcoumarin;    MHC;    major histocompatibility complex;    NEPHGE;    non-equilibrium pH gradient electrophoresis;    PAGE;    polyacrylamide gel electrophoresis;    Suc;    succinyl;    TAP;    transporter associated with antigen presentation;   

DOI  :  10.1016/0014-5793(96)00110-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

20S proteasomes of tissues from LMP7 knock out mice which show reduced MHC class I restricted antigen presentation were analyzed with regard to their subunit composition, peptide hydrolyzing activity and their ability to cleave a synthetic 25-mer polypeptide. LMP7 deficiency results in an enhanced incorporation of subunit MB1 and in a 2–3.8-fold increase in V _max for the Suc-LLVY-MCA hydrolyzing activity. Since LMP7 deficiency also affects the cleavage site preference of 20S proteasomes the reduced MHC class I antigen presentation of LMP7 knock out mice is most likely due to an impairment in peptide generation.

【 授权许可】

Unknown