The interactions between a few representative gold-based drugs and hen egg white lysozyme were studied by X-ray crystallography. High resolution crystal structures solved for three metallodrug-protein adducts provide valuable insight into the molecular mechanism of these promising metal compounds and the inherent protein metalation processes.

In contrast to hen egg-white lysozyme, which retains the beta-configuration of the substrate in the product, T4 lysozyme (T4L) is an inverting glycosidase. The substitution Thr-26 --> His, however, converts T4L from an inverting to a retaining enzyme. It is shown here that the Thr-26 --> His mutant is also a transglycosidase. Indeed, the transglycosylation reaction can be more effective than hy...

Lysozyme, an antibacterial protein, has been implicated in innate immunity in invertebrates, but its activity in shrimp remained to be determined. We cloned the white shrimp lysozyme cDNA using a PCR strategy and detected its activity in haemocytes using a lytic-zone assay against Micrococcus luteus. The cloning was based on a reported EST (dbEST BE18831). The deduced amino acid sequence result...

Amyloid aggregation of polypeptides is related to a growing number of pathologic states known as amyloid disorders. In recent years, blocking or reversing amyloid aggregation via the use of small compounds are considered as two useful approaches in hampering the development of these diseases. In this research, we have compared the ability of several manganese-salen derivatives, as synthetic com...

Chemical modification of proteins has been and continues to be an important biochemical tool for the study of protein structure and function. One such type of approach has been the reductive methylation of lysine residues. In order to address the consequences of such methylation on the crystallization and structural properties of a protein, the three-dimensional structure of hen egg white lysoz...

After the recent discovery of a ribonuclease A unfolding intermediate [Kiefhaber, T., et al. (1995) Nature 375, 513-515], we investigated the unfolding pathway of hen egg white lysozyme. At pH* 4.00 with D2O at 10 degrees C and 6 M guanidinium chloride, unfolding shows a single, slow kinetic phase, with a relaxation time of 3300 s when monitored by circular dichroism (CD). Exchange of the trypt...