کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2189866 1096225 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tandemization Endows Bovine Pancreatic Ribonuclease with Cytotoxic Activity
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Tandemization Endows Bovine Pancreatic Ribonuclease with Cytotoxic Activity
چکیده انگلیسی

Due to their ability to degrade RNA, selected members of the bovine pancreatic ribonuclease A (RNase A) superfamily are potent cytotoxins. These cytotoxic ribonucleases enter the cytosol of target cells, where they degrade cellular RNA and cause cell death. The cytotoxic activity of most RNases, however, is abolished by the cytosolic ribonuclease inhibitor (RI). Consequently, the development of RNase derivatives with the ability to evade RI binding is a desirable goal. In this study, tandem enzymes consisting of two RNase A units that are bound covalently via a peptide linker were generated by gene duplication. As deduced from the crystal structure of the RNase A·RI complex, one RNase A unit of the tandem enzyme can still be bound by RI. The other unit, however, should remain unbound because of steric hindrance. This free RNase A unit is expected to maintain its activity and to act as a cytotoxic agent. The study of the influence of the linker sequence on the conformation and stability of these constructs revealed that tandemization has only minor effects on the activity and stability of the constructs in comparison to monomeric RNase A. Relative activity was decreased by 10–50% and the melting temperature was decreased by less than 2.5 K. Furthermore, the cytotoxic potency of the RNase A tandem enzymes was investigated. Despite an in vitro inhibition by RI, tandemization was found to endow RNase A with remarkable cytotoxic activity. While monomeric RNase A is not cytotoxic, IC50 values of the RNase A tandem variants decreased to 70.3–12.9 μM. These findings might establish the development of a new class of chemotherapeutic agents based on pancreatic ribonucleases.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 358, Issue 5, 19 May 2006, Pages 1305–1313
نویسندگان
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