Wysokorozdzielcza krystalografia makromolekuł
Journal Title: Wiadomości Chemiczne - Year 2014, Vol 68, Issue 5
Abstract
The recent developments and availability of modern third-generation synchrotron radiation facilities have a huge impact on macromolecular X-ray crystallography. In connection with a number of methodological improvements and new crystallographic software ranging from data processing to refinement, a unique opportunity has arisen to determine the macromolecular structures with unprecedented high resolution and quality, at a level traditionally reserved for small molecules. At this resolution, individual atoms are clearly resolved and fine details of the structures become visible directly in the electron density maps. The great importance of such structures is the possibility of having broader insights into macromolecule function. At very high resolution, hydrogen atoms can be seen in electron density maps and the detailed information about the protonation states of catalytically important residues can be studied, what often is critical for full understanding of enzymatic reactions. Atomic resolution gives the opportunity for clear definition of multiple conformations, although the proportion of disordered residues is higher at higher resolution, and the disorder is seen as distinct alternative conformations. Water in macromolecular crystal plays an important role in macromolecule’s function and stabilization. Ultrahigh resolution data allows to refine water molecules with anisotropic displacement parameters and refine them with fractional occupancies. In this situation analyzing the subtle hydrogen bond network, involving precisely located water molecules, is possible. Atomic resolution structures can be refined without or with only very weak stereochemical restraints. Macromolecular models refined at ultrahigh resolutions, for well ordered structures, can be used for validation and improvement of stereochemical restraint libraries, commonly used during refinement of macromolecular structures.
Authors and Affiliations
Mirosław Gilski
Syntezy wybranych zasad Mannicha o aktywności przeciwbakteryjnej i przeciwgrzybiczej in vitro
The Mannich reaction is a three-component condensation reaction involving an active hydrogen containing compound, formaldehyde and a primary or a secondary amine. The Mannich reaction is one of the most important basic r...
Izoflawony – struktura, aktywność biologiczna oraz metody oznaczania przy użyciu wysokosprawnej chromatografii cieczowej
Isoflavones are a subclass of flavonoids and are also described as phytoestrogen compounds, since they exhibit estrogenic activity (similar effects to estradiol hormones). The basic characteristics of isoflavone structur...
Rutyna : budowa, właściwości
Flavonoids commonly can be found in plants. They protect them against various microorganisms or insects [1]. Flavonoids demonstrate not only antioxidant properties, but also prevent the development of cancer [2]. This is...
Max Rudolf Lemberg (1896–1975) – australijski biochemik o wrocławskich korzeniach
The article is devoted to Max Rudolf Lemberg (1896–1975), known primarily as an author of pioneering works on bile pigments and porphyrin degradation (in particular, coupled oxidation), and to his connections with Wrocła...
Chemiczne aspekty celowanej terapii przeciwnowotworowej II. Połączenia nośnik -lek
Traditional anticancer therapy is usually low effective. Popular and common drugs applied in anticancer therapy are characterized by low solubility and nonspecific biodistribution in an organism. The chemotherapy kills n...