Secretagogin is a calcium-sensor protein with six EF-hands. It is widely expressed in neurons and neuro-endocrine cells of a broad range of vertebrates including mammals, fishes and amphibia. The protein plays a role in secretion and interacts with several vesicle-associated proteins. In this work, we have studied the contribution of calcium binding and disulfide-bond formation to the stability...

We introduce a simplified protein model where the solvent (water) degrees of freedom appear explicitly (although in an extremely simplified fashion). Using this model we are able to recover the thermodynamic phenomenology of proteins over a wide range of temperatures. In particular we describe both the warm and the cold protein denaturation within a single framework, while addressing important ...

Alpha-Amylase from the antarctic psychrophile Altermonas haloplanktis is synthesized at 0 +/- 2 degrees C by the wild strain. This heat-labile alpha-amylase folds correctly when overexpressed in Escherichia coli, providing the culture temperature is sufficiently low to avoid irreversible denaturation. In the described expression system, a compromise between enzyme stability and E. coli growth r...

Differential scanning calorimetry was employed to investigate the structure of spinach (Spinacia oleracea) chloroplast membranes. In a low ionic strength Hepes-buffered medium, major calorimetric transitions were resolved at 42.5 degrees C. (A), 60.6 degrees C (B), 64.9 degrees C (C(1)), 69.6 degrees C (C(2)), 75.8 degrees C (D), 84.3 degrees C (E), and 88.9 degrees C (F). A lipid melting trans...

BACKGROUND Multiplexed detection of low-level mutations presents a technical challenge for many technologies, including cancer gene panels used for targeted-resequencing. Analysis of mutations below approximately 2%-5% abundance in tumors with heterogeneity, samples with stromal contamination, or biofluids is problematic owing to increased noise from sequencing errors. Technologies that reduce ...

Bulk crystallisation of protein therapeutic molecules towards their controlled drug delivery is of interest to the biopharmaceutical industry. The complexity of biotherapeutic molecules is likely to lead to complex material properties of crystals in the solid state and to complex transitions. This complexity is explored using batch crystallised lysozyme as a model. The effects of drying and mil...

We compared thermally induced denaturation and aggregation of two isoforms of the isolated myosin head (myosin subfragment 1, S1) containing different "essential" (or "alkali") light chains, A1 or A2. We applied differential scanning calorimetry (DSC) to investigate the domain structure of these two S1 isoforms. For this purpose, a special calorimetric approach was developed to analyze the DSC ...

Thermal denaturation of chromatin is observed by simultaneously monitoring absorption and circular dichroism at 276 nm as functions of temperature. Either observation indicates that sheared chromatins shows less thermal stability than native chromatin. The temperature-dependent ellipticities at 276 nm of these chromatins show features not seen in the absorption curves: the ellipticity of unshea...

Thermal lability of bovine erythrocyte membrane proteins was studied by electron spin resonance using maleimide spin label. The temperature of the sample during measurements could be varied for the first time between 0 and 60 degrees C with an accuracy of +/- 0.1 degrees C. Our results show that "old" erythrocyte membrane proteins are less stable against thermal denaturation then "young" cells.

BACKGROUND DNA genotyping with mutation-specific TaqMan(R) probes (Applied Biosystems) is broadly used in detection of single-nucleotide polymorphisms but is less so for somatic mutations because of its limited selectivity for low-level mutations. We recently described coamplification at lower denaturation temperature-PCR (COLD-PCR), a method that amplifies minority alleles selectively from mix...