The tertiary structure of myoglobin is that of a typical water soluble globular protein. Its secondary structure is unusual in that it contains a very high proportion (75%) of α-helical secondary structure. A myoglobin polypeptide is comprised of 8 separate right handed α-helices, designated A through H, that are connected by short non helical regions. Amino acid R-groups packed into the interi...

In this paper, we seek to compare the internal dynamics of a small globular protein, SH3 domain from alpha-spectrin, in solution and in a crystalline state. The comparison involves side-chain methyl 13C R1 relaxation rates that are highly sensitive to local dynamics in the vicinity of the methyl site. To conduct the relaxation measurements, protein samples have been prepared using specially lab...

The small globular protein, ubiquitin, contains a pair of oppositely charged residues, K11 and E34, that according to the three-dimensional structure are located on the surface of this protein with a spatial orientation characteristic of a salt bridge. We investigated the strength of this salt bridge and its contribution to the global stability of the ubiquitin molecule. Using the "double mutan...

Many biologically interesting functions such as allosteric switching or protein-ligand binding are determined by the kinetics and mechanisms of transitions between various conformational substates of the native basin of globular proteins. To advance our understanding of these processes, we constructed a two-dimensional free energy surface (FES) of the native basin of a small globular protein, T...

To study the factors determining the collective motions in thermal, conformational fluctuations of a globular protein, molecular dynamics simulations were performed with a backbone model and an atomic-level model. In the backbone model, only the C alpha atoms were explicitly treated with two types of pairwise interactions assigned between the C alpha atoms; atom-packing interactions to take int...

Analyses of solution (15)N relaxation data and solid-state (1)H(N)-(15)N dipolar couplings from a small globular protein, alpha-spectrin SH3 domain, produce a surprisingly similar pattern of order parameters. This result suggests that there is little or no ns-mus dynamics throughout most of the sequence and, in particular, in the structured portion of the backbone. At the same time, evidence of...

Protecting osmolytes are widespread small organic molecules able to stabilize the folded state of most proteins against various denaturing stresses in vivo. The osmophobic model explains thermodynamically their action through a preferential exclusion of the osmolyte molecules from the protein surface, thus favoring the formation of intrapeptide hydrogen bonds. Few works addressed the influence ...

We present the results of a Chandra/HST study of the point sources of the Virgo cluster giant elliptical galaxy NGC 4472. We identify 144 X-ray point sources outside the nuclear region, 72 of which are located within the HST fields. The optical data show 1102 sources, of which 829 have colors consistent with being globular clusters (with only 4 in the restricted central 10” region). Thirty matc...

A new look at globular cluster colors in NGC 3311 and the case for exclusively metal–rich globular cluster systems ABSTRACT NGC 3311, the central cD galaxy in the Hydra cluster, was previously thought to host the most metal–rich globular cluster system known. Ground–based Washington photometry had indicated the almost complete absence of the population of globu-lar clusters near [Fe/H] ∼ −1 dex...

The Sombrero galaxy, NGC 4594, contains the most numerous globular cluster system of any nearby spiral. It is an ideal candidate in which to study the globular clusters and contrast them with those in Local Group spirals. Here we present B and I imaging from the CTIO Schmidt telescope which gives a field-of-view of 31 ′ × 31 ′ . Using DAOPHOT we have detected over 400 globular clusters and deri...