Structural analysis of proteins

Analysis of CD spectra

Selvita offers determination of the percentage of protein secondary structures (α-helices, β-structures and unstructured regions) by the circular dichroism method. The far-UV CD (190-240 nm) corresponds to the peptide bond absorption and allow estimation of the content of α-helices, β-sheets, turns and random motifs. The near-UV CD (250-320 nm) reflects the environment of the aromatic amino acid side chains and allows comparative estimations of the tertiary structure.

Crystallographic analyses of proteins

Our offer includes contract research or implementation of joint research projects in the field of X-ray crystallography of biological macromolecules. We perform a full set of necessary experimentation, providing high-resolution tertiary structures of proteins in the free state and in complexes with low molecular weight ligands.

In addition, we offer a comprehensive analysis of the results of the experiments involving characteristics of binding pocket and suggestions for further optimization of ligands as well as docking ligands in silico. Understanding of the ligand binding mode is very important in the new approach in drug discovery which is called ‘structure-based drug design’. Analysis of binding pocket provides an insight in mechanism of action of the ligand at the molecular level which gives information about further optimization of the ligand structure.

We also perform a comparative analysis of biosimilar drugs at structural level. This kind of analyses is needed when new generic biosimilar drug is compared with its counterpart existing on the market (e.g. comparison of new human insulin analogue with human insulin).

Screening of the crystallization conditions, typically over 1 000 crystallization conditions are screened to establish the optimal protein crystallization conditions.

Optimization of pre-established crystallization conditions together with initial measurements, Determination of protein structure by X-ray crystallography requires high quality diffracting crystal, the pre-established crystallization conditions often require further optimization.

X-ray diffraction and structure solution, a full set of X-ray diffraction data is generated, based on which the tertiary structure of recombinant protein is solved at atomic resolution by the use of Molecular Replacement (MR) for phase method.

Structure Based Drug Design (SBDD)

Selvita has developed a platform for investigation of protein structures to meet our Customer’s needs. It includes complete Gene-to-Structure services as well as protein structure determination based on Customer-provided proteins/crystals. In Gene-to-Structure approach, we offer full package of services including: protein expression, purification, crystallization (apo-enzyme, protein-ligand and protein-protein complexes, co-crystallization or soaking) followed by structure determination. Fragments screening and ligand binding experiments are fully supported by theoretical calculations and docking simulations.