Investigation of Amorphous Carbon in Nanostructured Carbon Materials (A Comparative Study by TEM, XPS, Raman Spectroscopy and XRD).

Amorphous carbon (AC) is present in the bulk and on the surface of nanostructured carbon materials (NCMs) and exerts a significant effect on the physical, chemical and mechanical properties of NCMs. Thus, the determination of AC in NCMs is extremely important for controlling the properties of a wide range of materials. In this work, a comparative study of the effect of heat treatment on the structure and content of amorphous carbon in deposited AC film, nanodiamonds, carbon black and multiwalled carbon nanotube samples was carried out by TEM, XPS, XRD and Raman spectroscopy. It has been established that the use of the 7-peak model for fitting the Raman spectra makes it possible not only to isolate the contribution of the modes of amorphous carbon but also to improve the accuracy of fitting the fundamental G and D2 (D) modes and obtain a satisfactory convergence between XPS and Raman spectroscopy. The use of this model for fitting the Raman spectra of deposited AC film, ND, CB and MWCNT films demonstrated its validity and effectiveness for investigating the amorphous carbon in various carbon systems and its applicability in comparative studies of other NCMs.

ZAD-Domain Is Essential for Nuclear Localization of Insulator Proteins in Drosophila melanogaster.

Many arthropod zinc-finger transcription factors contain a N-terminal domain called ZAD (Zinc-finger Associated Domain), which consists of four cysteines coordinating a single zinc ion. Dimerization ability has been shown for several ZAD-domains. The functional role of this domain is poorly understood. In this paper, we demonstrate that a point mutation within the ZAD-domain of the Zw5 insulator protein disrupts its nuclear localization without affecting its dimerization ability. The importance of the ZAD-domain for nuclear localization has also been shown for the Pita and Grauzone proteins. Therefore, one of the ZAD-domain functions is control of the nuclear localization of transcription factors.

[Translation elongation factor EF1α1 interacts with ZAD domains of transcription factors from Drosophila melanogaster].

A large class of arthropod transcription factors is formed by proteins with a characteristic N-terminal Zinc-finger-Associated Domain (ZAD) which contains four cysteine residues that coordinate a zinc ion. The number of putative proteins with ZAD in the Drosophila genome exceeds 90, and the degree of sequence similarity between these domains can be as low as 23%. Efficient binding of ZADs from the proteins Grau, ZIPIC, and Zw5 to the translation elongation factor EF1α1 in nuclear and cytoplasmic extracts has been demonstrated. EF1α1 is probably involved in the regulation of the activity of ZAD-containing transcription factors.

[Recruiting of insulator protein ZIPIC of Drosophila melanogaster to minor binding sites in vivo depends on other DNA-binding transcription factors].

ZIPIC insulator protein of Drosophila has seven zinc finger domains at the C-terminus. Some of this zinc fingers are involved in binding of specific DNA sequence: CAGGGCTG. ZIPIC can interact only in vivo with minor form of this site (substitution of G to T at position 4). Possible explanation is interaction with additional transcription factors can help ZIPIC to bind minor form of consensus. On the other hand ZIPIC can efficiently bind in vitro other minor form of consensus (substitution of C to A at 6 position).