| AVS 57th International Symposium & Exhibition | |
| Biomaterial Interfaces | Thursday Sessions |
| Session BI-ThP |
| Session: | Biomaterial Interfaces Poster Session |
| Presenter: | M. Anderle, Ict - Pat, Italy |
| Authors: | L. Marocchi, Center for Materials and Microsystems - FBK, Italy L. Lunelli, Center for Materials and Microsystems - FBK, Italy G. Viero, CiBio – University of Trento, Italy F. Piras, Center for Materials and Microsystems - FBK, Italy N. Arseni, CiBio – University of Trento, Italy A. Provenzani, CiBio – University of Trento, Italy C. Pederzolli, Center for Materials and Microsystems - FBK, Italy A. Quattrone, CiBio – University of Trento, Italy M. Anderle, Ict - Pat, Italy |
| Correspondent: | Click to Email |
The cellular machinery dedicated to the synthesis of the polypeptide chain translated from the mRNA template is the ribosome. Clusters of translating ribosomes held together by mRNA form the so-called polysome. The study of such supramolecular assemblies has interests both in structural and functional aspects as addressed in this study. As consequence the analyses of polysomal mRNA are emerging as good estimators in directly representing cell phenotypes. Since traditional methods of polysome purification are still a time consuming and laborious procedures, high throughput polysomal purifications are attracting growing interest. Recently, more modern approaches have been developed, based on the specific affinity between genetically modified ribosomes and functional surfaces. However, native ribosomes are required for several analytical applications. This work is a first step in developing a convenient and fast strategy to purify native polysomes thanks to their adhesion ability to appropriate substrates. We studied the interaction between functionalized gold surfaces and polysome fractions purified from human cultured cells or ribosomes derived from rabbit reticulocyte lysate. Surfaces endowed with different chemical properties were obtained using functional thiols able to form self assembled monolayers on gold substrates. Substrate surface properties were studied with XPS, ToF-SIMS and AFM. The interaction of rabbit ribosomes with the surfaces was assessed with AFM and confocal microscopy.
Despite different imaging approaches have been used to visualize bacterial and eukaryotic polysomes, human native polysomes have never been observed in physiological conditions. Moreover nothing is known about the formation of the mRNA-ribosomes macroassembly. Here we present the very first AFM images of native polysomes from mammalian cell lines adherent to surfaces. For the first time to our knowledge, we could observe ribosome aggregates associated to RNA, providing the imaging of polysome assemblies. Our imaging approach suggests the existence of a complex pattern of conformations and reveals novel levels of polysomal organization.