The molecular organization of adrenocortical cytochrome P-450scc has been investigated using chemical modification with bifunctional imidates. The oligomeric organization of cytochrome P-450scc in solution has been shown. The application of dimethyl-3,3'-dithiobispropioimidate and subsequent cleavage of the modified products by reducing agents revealed the presence of two types of intramolecula...

A simple method for the preparation of HeLa cell plasma membrane ghosts without the use of cross-linking reagents or Cxatives has been developed. The membranes have been characterized by phase and electron microscopy and by the use of radioactive precursors to RNA, protein, glycoprotein, and lipid. The glycoprotein and polypeptide constituents have been analyzed by sodium dodecyl sulfate-acryla...

SBP2 is a pivotal protein component in selenoprotein synthesis. It binds the SECIS stem-loop in the 3' UTR of selenoprotein mRNA and interacts with both the specialized translation elongation factor and the ribosome at the 60S subunit. In this work, our goal was to identify the binding partners of SBP2 on the ribosome. Cross-linking experiments with bifunctional reagents demonstrated that the S...

UNLABELLED BACKGROUND Biosensors have attracted increasing attention as reliable analytical instruments in in situ monitoring of public health and environmental pollution. For enzyme-based biosensors, the stabilization of enzymatic activity on the biological recognition element is of great importance. It is generally acknowledged that an effective immobilization technique is a key step to ac...

Role of disulfide bridges in phytase's unfolding-refolding was probed using dynamic light scattering. Phytase was unfolded by guanidinium chloride and then refolded by removing the denaturant by dialysis. Thiol reagents prevented refolding; thus, disulfide bridge formation is an integral step in phytase folding. Catalytic demise of phytase after unfolding and refolding in presence of Tris(2-car...

Bifunctional reagents have recently been used in several studies (l-4) concerned with the stereochemistry of proteins in solution. The objective was to link proximal pairs of functional groups of a protein molecule by means of bifunctional reagents in order to introduce artificial cross-links stable enough to withstand chemical and enzymatic degradative procedures. The expectation was that only...

The cross-linking Mass Spectrometry (XL-MS) technique extracts structural information from protein complexes without requiring highly purified samples, crystallinity, or large amounts of material. However, there are challenges to applying the technique to protein complexes in vitro, and those challenges become more daunting with in vivo experiments. Issues include effective detection and identi...

The Mr 8,000 light chain originally identified in Chlamydomonas flagellar dynein is also a component of both cytoplasmic dynein and myosin V. Furthermore, this small protein has been implicated as an inhibitor of neuronal nitric oxide synthase, suggesting that it may play multiple regulatory roles within the cell. Covalent cross-linking of both dynein and myosin V using 1,5-difluoro-2, 4-dinitr...

In recombinant N-methyl-D-aspartate (NMDA) receptors, two redox modulatory sites are thought to exist, one formed by Cys744 and Cys798 on NMDA receptor subunit (NR) 1, and a second one, not yet localized, on NR2A. Reductants increase the open dwell-time and opening frequency of NR1/NR2A channels. In contrast, NR1/NR2B and NR1/NR2C channels exhibit changes only in opening frequency after redox t...