Covalent immobilization of Proteinase K and Catalase onto single-walled carbon nanotubes: secondary structure and thermal stability

سال انتشار: 1389
محل انتشار: اولین کنفرانس ملی علوم و فناوری نانو
کد COI اختصاصی: NNTC01_221
زبان مقاله: انگلیسی
تعداد مشاهده: 1907

دانلود فایل این مقاله

نویسندگان

Mostafa jamalan

Isalamic Azad University, Shoushtar Branch, Shoushtar

Latifeh choupani

Khoramshahr marine science and technology university, khoramshahr, Iran

Meysam farzadi

Islamic Azad University, Karaj, Iran

Majid zeinali

Biotechnology Research Center, Research Institute of Petroleum Industry (RIPI), Tehran, Iran

چکیده

Stabilization of enzymes against extreme conditions etc. high temperature is one of the most complicated challenges in protein science. Amino acids substitution, chemical modification and protein immobilization on various support materials are the main classical strategies for enzyme stabilization. Carbon nanotube (CNT) as a nano-scale material with dedicated attributes, like enormous rigidity, stability and resistance to bio- and chemical degradation, could be used as a good candidate for enzyme immobilization. In the current study, catalase and proteinase K were covalently immobilized onto single-walled carbon nanotube (SWCNT). Enzyme functionalization of carboxylated SWCNTs was performed using carbodiimide chemistry according to Jiang method. Briefly, N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) was used for coupling of N-hydroxysuccinamide (NHS) to the carboxylic groups on the oxidized nanotubes. The resulting stable active esters on CNTs were reacted with the amine groups on the catalase and proteinase K. Secondary structures of CNT-conjugated forms of enzymes were assessed byCD spectrophotometry. Catalase activity was measured using H2O2 as substrate and proteinase K activity was determined via the hydrolysis of casein. Thermal stabilization was followed by fluorescence spectrophotometry at different temperatures. Catalase and proteinase K in conjugation with SWCNT remain kinetically active. Conjugation to SWCNTs could induce extensive changes in the secondary structure of catalase. In contrast, the secondary structure of proteinase k in the conjugated form remains unchanged in comparison to unconjugated form. Immobilization of proteinase K on SWCNTs could stable its structure against high temperature but conjugation of catalase to SWCNTs had no obvious effect on its thermostability. It seems that immobilization of proteins on CNTs to obtain thermostable biocatalysts could not be used as a general route for any enzyme.

کلیدواژه ها

مقالات مرتبط جدید

اطلاعات بیشتر در مورد COI

COI مخفف عبارت CIVILICA Object Identifier به معنی شناسه سیویلیکا برای اسناد است. COI کدی است که مطابق محل انتشار، به مقالات کنفرانسها و ژورنالهای داخل کشور به هنگام نمایه سازی بر روی پایگاه استنادی سیویلیکا اختصاص می یابد.

کد COI به مفهوم کد ملی اسناد نمایه شده در سیویلیکا است و کدی یکتا و ثابت است و به همین دلیل همواره قابلیت استناد و پیگیری دارد.