تقرير
Carboplatin binding to a model protein in non-NaCl conditions to eliminate partial conversion to cisplatin, and the use of different criteria to choose the resolution limit
العنوان: | Carboplatin binding to a model protein in non-NaCl conditions to eliminate partial conversion to cisplatin, and the use of different criteria to choose the resolution limit |
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المؤلفون: | Tanley, Simon W. M, Diederichs, Kay, Kroon-Batenburg, Loes M. J, Schreurs, Antoine M. M, Helliwell, John R |
سنة النشر: | 2013 |
المجموعة: | Quantitative Biology |
مصطلحات موضوعية: | Quantitative Biology - Biomolecules |
الوصف: | Hen egg white lysozyme (HEWL) co-crystallisation conditions of carboplatin without sodium chloride (NaCl) have been utilised to eliminate partial conversion of carboplatin to cisplatin observed previously. Tetragonal HEWL crystals were successfully obtained in 65% MPD with 0.1M citric acid buffer at pH 4.0 including DMSO. The X-ray diffraction data resolution to be used for the model refinement was reviewed using several topical criteria together. The CC1/2 criterion implemented in XDS led to data being significant to 2.0{\AA}, compared to the data only being able to be processed to 3.0{\AA} using the Bruker software package (SAINT). Then using paired protein model refinements and DPI values based on the FreeR value, the resolution limit was fine tuned to be 2.3{\AA}. Interestingly this was compared with results from the EVAL software package which gave a resolution limit of 2.2{\AA} solely using crossing 2, but 2.8{\AA} based on the Rmerge values (60%). The structural results showed that carboplatin bound to only the N{\delta} binding site of His-15 one week after crystal growth, whereas five weeks after crystal growth, two molecules of carboplatin are bound to the His-15 residue. In summary several new results have emerged: - firstly non-NaCl conditions showed a carboplatin molecule bound to His-15 of HEWL; secondly binding of one molecule of carboplatin was seen after one week of crystal growth and two molecules were bound after five weeks of crystal growth; and thirdly the use of several criteria to determine the diffraction resolution limit led to the successful use of data to higher resolution. Comment: 14 pages; submitted to Acta Cryst D Biological Crystallography reference number tz5044 |
نوع الوثيقة: | Working Paper |
URL الوصول: | http://arxiv.org/abs/1309.4661 |
رقم الأكسشن: | edsarx.1309.4661 |
قاعدة البيانات: | arXiv |
الوصف غير متاح. |