Structural characterization of Stanniocalcin-1 by Structural Proteomics

Author(s)

Állan Jhonathan Ramos Ferrari

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2015-02-24

Examining board members

Fábio Cesar Gozzo; Vitor Marcelo Silveira Bueno Brandão de Oliveira; Carlos Henrique Inacio Ramos

• Advisor: Fábio Cesar Gozzo

Abstract

The Stanniocalcin-1 (STC1) is a glycoproteic hormone, which shows a differential expression pattern in a variety of pathologies, especially in neoplasia, but its functional and structural aspects have not been explored. Accordingly, the STC1 was chosen as a target to the use of an integrative approach including chemical cross-linking, mass spectrometry and molecular modeling. From cross-linking experiments,37 distance constrains were identified involving the DSS cross-linker, 11 of them in the N-terminus part of the protein and one involving the dimeric specie, in addition to five disulfide bonds already published. These constrains were used to generate structural models by I-Tasser and Quark online platforms and, locally, more than 100,000 models in the Ab Initio Relax protocol package present in the Rosetta software in four different modeling conditions. Rosetta was the most efficient in generating models when secondary structure prediction was absent. The distance constrains were found to be a key discriminatory tool for the selection of candidate structures for the STC1. For the 1,500 lowest score structures that satisfied the distance constrains, the clustering method employing the global distance test parameter (gdt) identified 22 structurally distinct representative structures. These representative structures can be used to in molecular replacement test to solve the X-Ray diffraction data (AU)

• FAPESP's process: 13/23814-3 - Structural caracterization of Stanniocalcin-1 by advanced structural proteomics
• Grantee: Allan Jhonathan Ramos Ferrari
• Support Opportunities: Scholarships in Brazil - Master