Protein and Peptide Letters - Volume 13, Issue 3, 2006

Protein aggregation has long been experienced as an important problem in the biotechnology industry. It was more recently suggested that a range of disorders including amyloid diseases such as Alzheimer's and Parkinson's diseases and type II diabetes, as well as some forms of cancer are associated with protein misfolding and aggregation. Today, it is generally accepted that aberrant protein aggregation results from the fa Read More

One of the hallmarks of modern science is technically controlled experimentation. In this paper, we underline how technical developments over the last 150 years have repeatedly created new horizons in amyloid research. The main focus is on chemical and biophysical analyses of amyloid fibrils in vivo and in vitro. Investigations into mechanistic aspects of fibril formation and possible links with pathogenesis are also discussed.

Protein molecules have emerged through evolution so that they are able to remain in their functional and soluble states under normal physiological conditions, although in other situations they often have a high propensity to aggregate. Aggregation in vivo is associated with a wide range of human disorders, including Alzheimer's disease and type II diabetes, medical conditions that are becoming increasingly common in the Read More

Solid state nuclear magnetic resonance (NMR) has developed into one of the most informative and direct experimental approaches to the characterization of the molecular structures of amyloid fibrils, including those associated with Alzheimer's disease. In this article, essential aspects of solid state NMR methods are described briefly and results obtained to date regarding the supramolecular organization of amyloid fibri Read More

The neuronal Tau protein, whose physiological role is to stabilize the microtubules, is found under the form of aggregated filaments and tangles in Alzheimer's diseased neurons. Until recently detailed structural analysis of the natively unfolded Tau protein has been hindered due to its shear size and unfavourable amino acid composition. We review here the recent progress in the assignments of the full-length polypeptide using n Read More

Quasielastic light scattering spectroscopy (QLS) is an optical method for the determination of diffusion coefficients of particles in solution. Here we discuss the principles of QLS and explain how the distribution of particle sizes can be reconstructed from the measured correlation function of scattered light. Non-invasive observation of the temporal evolution of particle sizes provides a powerful tool for studying protein assemb Read More

Mass spectrometry has become increasingly important in amyloid research specifically in the mechanism of formation and characterization of fibrils. In this review we highlight key experiments that provide evidence for different conformations, interactions and unfolding intermediates in proteins associated with amyloid diseases.

The atomic force microscope (AFM) is a versatile instrument that can be used to image biological samples at nanometre resolution as well as to measure inter and intra-molecular forces in air and liquid environments. This review summarises the use of AFM applied to protein and peptide self-assembly systems involved in amyloid formation. The technical principles of the AFM are outlined and its advantages and disadvantages Read More

A common mechanism of conformational changes and pathological aggregation of proteins associated with amyloid diseases remains to be proven. High pressure is emerging as a new strategy for studying aspects of amyloid formation. Pressure provides a convenient means to populate and characterize partially folded states, which are thought to have a key role in assembly processes of proteins into amyloid fibrils. High Read More

Elucidation of the molecular determinants that drive proteins to aggregate is important both to advance our fundamental understanding of protein folding and misfolding, and as a step towards successful intervention in human disease. Combinatorial strategies enable unbiased and model-free approaches to probe sequence/structure relationships. Through the use of combinatorial methods, it is possible (i) to probe the sequenc Read More

The process of protein misfolding and aggregation has been associated with an increasing number of pathological conditions that include Alzheimer's and Parkinson's diseases, and type II diabetes. In addition, the discovery that proteins unrelated to any known disorder can be converted into aggregates of morphologies similar to those found in diseased tissue has lead to the recognition that this type of assembl Read More

We hereby report on a mutational analysis of a novel natriuretic peptide (PNP), recently isolated by us from the Iranian snake venom. The PNP variant (mutPNP) with four substitutions (G16T, K18S, R21S, G23R) and a disulfide bonded ring shortened by 3 residues. mutPNP peptide was expressed in pET32 and purified by affinity separation on nickel resin followed by RP-HPLC chromatography. The conformation of mutPN Read More

Functional S100P requires dimer formation and dimerization might form for one of the two reasons: i. producing a pair of site for target protein binding or ii. modulation of cation binding affinity. The extent of exposed protein hydrophobicity was related to dimer formation.

Interaction between S100P and its target protein is an essential step in several cellular functions. The amphiphatic mellitin peptide binds tightly to S100P protein in the presence of calcium cation. Since little is known about the recognition sequence, mellitin interaction form a model for S100P. Interaction between mellitin and protein examined to identify key regions required for the protein-protein interaction.

S-adenosylmethionine decarboxylase (AdoMetDC) is a key enzyme in the biosynthesis of the polyamines spermidine and spermine. Polyamines are ubiquitous organic cations that are absolutely required for normal cell proliferation and differentiation. AdoMetDC catalyzes decarboxylation of S-adenosylmethionine (AdoMet) which provides aminopropyl groups for spermidine and spermine synthesis. Mammalian AdoMetDC is pro Read More

Mabinlin II is a thermostable sweet protein isolated from the mature seeds of Capparis masaikai Levl. grown in the subtropical region of the South of China. The Mabinlin II has been crystallized and diffraction data were collected to 1.7 Å resolution. The crystal belongs to space group C2 with unit cell parameters a = 80.11 Å, β = 51.08 Å, c = 47.34 Å, b = 122.77° .