Structure-function analysis and characterization of metalloproteins.

Metalloproteins are proteins that can bind at least one metal ion as a cofactor. They utilize metal ions for a variety of biological purposes, and are essential for all domains of life. Due to the ubiquity of metalloprotein’s involvement across these processes across all domains of life, how proteins coordinate metal ions for different biochemical functions is of great relevance to understanding the implementation of these biological processes. One of the most important aspects of metal binding is its coordination geometry (CG), which often implies functional activities. Most of the current studies are based on the assumption of previously reported CG models founded mainly in a non-biological chemical context. While this general procedure provides us with great measures on the closest CG model a metal site adopts, it also biases and limits the binding ligand selection and coordination results to the canonical CG models examined. Thus, if a CG model exists that has never be reported previously or is not accounted for in a study, instances from the CG would either be misclassified into an expected model and cause a high in-class variation or considered as outliers. To solve this problem, we have developed our analysis, where the less-biased low-variation measure, bond-length, was used determine the binding ligands and the higher-variation measure, angle, was used to cluster the metal shells into canonical or novel CGs with functional associations. This methodology is model-free, and allows us to derive the CG models from the data itself. Thus, we can handle unknown CGs that may cause problems to the classification methods. This new methodology has enabled the discovery of several previously uncharacterized CGs for zinc and other top abundant metalloproteins. By recognizing these novel/aberrant CGs in our clustering analyses, high correlations were achieved between structural and functional descriptions of metal ion coordination

Unstiffened Elements - Some Interesting Features

The behaviour of members composed of unstiffened elements is examined with reference to three different sets of test results, on angle section struts, Tee section beams and shallow Vee section beams. The test results are explained on the basis of fairly simple analysis, and the variations of the behaviour from that predicted by modem design codes is discussed

Effect of corrosion on the buckling of steel angle members - experimental study

The aim of this work is to study the effect of corrosion on the buckling behaviour and resistance of corroded steel angle section members. The influences of the corrosion location and the loss of cross-section are studied by experimental investigations, where the corrosion is modelled by artificial thickness reduction. Compressive buckling tests are carried out on twenty-four specimens. Different corrosion damages are modelled, like uniform, pitting and local corrosion in the specimens. The buckling behaviour and the relationship of the corrosion reduction and the resistance decrease are determined