The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The rules that govern the folding of membrane proteins are still not completely understood when compared with the well-detailed set of principles described for the folding of soluble proteins. Although the molecular determinants of the folding mechanism should be basically the same for both types of proteins, the main difference, which in turn could also represent the main difficulty, is the media...
The knowledge of the molecular structure is the first step in comprehending how a protein works. The second level consists of understanding its mobility features. NMR is the only technique that allows the characterization of these two properties. Here, we will describe the relationships between the dynamics of a protein and some Nuclear Magnetic Resonance (NMR) parameters easily achievable, concretely,...
The interior of cells in all living organisms, without exception, has a common feature: the high total concentration of macromolecules they contain, which occupy a considerable fraction (20–30%) of the total volume. For example, macromolecular concentration of the E. coli intracellular media is around 400 mg/ml (Record et al. 1998, Zimmerman and Trach 1991), the concentration of hemoglobin in the...
Summary Current knowledge of protein-protein interactions in proteome is very limited due to the lack of high throughput and efficient experimental techniques at the protein levels. In this chapter, we briefly discuss the techniques currently available to determine protein-protein interactions and then focus on a novel technique developed by manipulating genome composition in common wheat. Genome...
Summary Post-translational modification of proteins is crucial for dynamic regulation and control of cellular processes. In eukaryotic cells, a subset of post-translationally modified membrane proteins is attached to the external leaflet of the plasma membrane by a glycosyl-phosphatidylinositol (GPI) anchor. There is substantial evidence suggesting that GPI-anchored proteins are clustered in sphingolipid-sterol...
Lectins are a structurally heterogeneous group of carbohydrate-binding proteins of non-immune origin comprising distinct families of evolutionarily related proteins (van Damme et al. 1998) (consult also the 3D Lectin Database at http://www.cermay.cnrs.fr /databank/lectine). Sugar recognition mechanisms have evolved independently in diverse protein frameworks, and lectins are ubiquitous in animals,...
Elucidating the nature of the relationships between the structure and function of biomolecules remains the key problem that molecular biologists need to solve in order to complete their reductionist agenda. According to Francis Crick (1966): “The aim of the modern movement in biology is to explain all biology in terms of physics and chemistry ”. This reductionist credo disregards the fact that biological...
The concept of protein function is widely used by biologists. However, the means of the concept and its understanding can vary largely depending on the functional level under consideration (molecular, cellular, physiological, etc.) Function is therefore a complex notion and the development of efficient ways of representing function which can be computer-tractable is presently the goal of many research...
The ribosome decodes the genetic information, controls the fidelity of codon-anticodon interactions, and catalyzes the peptide bond formation. However, none of these functional properties can be detected in free rRNAs, because ribosomal proteins and ions are required for the attainment of the rRNA proper tertiary structure (Burma et al. 1985). Despite the fact that the binding sites of ribosomal proteins...
Many biological signalling pathways are regulated by specific protein-protein interactions. The ability to measure such interactions in real time with high sensitivity using instrumental optical biosensors has resulted in the rapid expansion in the use of these technologies for characterising the physicochemical parameters in many biological signalling pathways (Nice and Catimel 1999, Rich and Myszka...
Protein-protein interactions play a central role in almost all aspects of the living cell, and understanding these interactions holds the key to understanding a host of cellular processes. Whether it is an enzyme modifying its substrate, the assembly of subunits of a multiprotein complex, the recognition and binding of a specific ligand, or the polymerization of monomeric subunits such as those of...
Non-covalent macromolecular interactions is nowadays one of the most challenging fields of postgenomic biology. Genome projects have revealed that the true complexity of cellular biology exists at the level of proteins rather than at the level of genes (Pandey and Mann 2000). From the raw genetic sequences many important properties of proteins, such as three-dimensional structure, function, cellular...
Tools for protein quantitation have advanced through several phases. Common proteins in readily studied sources, albumin and globulins in plasma, were discovered in the nineteenth century and quantified by gravimetric mass determination of chemical precipitates. Finer fractionations and scales led to quantitation of increasingly less common proteins, but the method has obvious limits. Some proteins,...
Meningococcal disease continues to be a worldwide health problem and can lead to death within several hours if untreated (Begg et al. 1999). There is currently no vaccine to prevent serogroup B meningococcal disease. The proteins which form the transferrin receptor of Neisseria meningitidis are promising candidates for inclusion in such a vaccine (Gorringe et al. 1995). The receptor consists of two...
Two-dimensional electrophoresis (2-DE) is the leading tool in proteomics research today, capable of visualising many components of complex proteomes in a single gel (Gorg et al. 2000). This tool separates proteins by pI (isoelectric point) and molecular weight producing a pattern of spots on an SDS-PAGE (polyacrylamide gel electrophoresis) gel, which can be visualised via a range of staining and labelling...
This paper describes our efforts to investigate the role of specific bacterial and eukaryotic ribosomal proteins in crucial cell functions such as elongation arrest of the nascent polypeptides and cell differentiation. These objectives have been approached by: (1) engineering the L4 bacterial ribosomal protein, which has been shown by crystallographic data to be a candidate molecule for controlling...
The ability of MALDI-MS to analyze photolabile arylazido peptide derivatives was investigated. Peptides containing UV-labile p-azidobenzoyl groups were subjected to MALDI-MS analysis in a variety of matrices. As a standard MALDI-MS employs a UV laser (337 nm), we investigated conditions that would allow detection of the intact molecule ions for these modified peptides. When using a-cyano-4-hydroxycinnamic...
A variety of applications in the proteomics field still rely on the Edman sequencing: The method is used to confirm MS data, to identify the amino-terminus, for heterogeneity assignment, domain structure analysis or the determination of proteolysis sites. However, the major benefit of the Edman sequencing method is clearly its de novo sequencing and quantification capability and, hence, it is still...
Knowledge of protein and peptide sequences is fundamentally important for understanding many physiological and biochemical processes at the molecular level. Chemically assisted fragmentation by MALDI (matrix-assisted laser desorption/ionization mass spectrometry) is a new approach for amino acid sequencing of tryptic peptides. The technology is based on a new class of water stable sulfonation reagents,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.