temporary banners

 



 

Journal Issue - Volume 14 Issue 6 (June 2005)

  • Proteins from PHB granules

  • George Georgiou, Ki Jun Jeong
  • Published in Wiley Interscience on Jan 01, 2009
  • DOI: 10.1110/ps.051418305 (p 1385-1386)

Abstract This work combines two well‐established technologies to generate a breakthrough in protein production and purification. The first is the production of polyhydroxybutyrate (PHB) granules in engineered strains of Escherichia coli. The second is a recently developed group of self‐cleaving affinity tags based on protein splicing elements known as inteins. By combining these technologies with a PHB‐specific binding protein, a self‐contained...

Abstract p25α is a 219‐residue proteinwhich stimulates aberrant tubulin polymerization and is implicated in a variety of other functions. The protein has unusual secondary structure involving significant amounts of random coil, and binding to microtubules is accompanied by a large structural change, suggesting a high degree of plasticity. p25α has been proposed to be natively unfolded, so that folding is coupled to interaction with...

Abstract Human Securin, also called PTTG1 (pituitary tumor transforming gene 1 product), is an estrogen‐regulated proto‐oncogene with multifunctional properties. We characterized human full‐length Securin using a variety of biophysical techniques, such as nuclear magnetic resonance, circular dichroism, and size‐exclusion chromatography. Under physiological conditions, Securin is devoid of tertiary and secondary structure except for...

Abstract Calcitonin, a peptide hormone associated with medullary carcinoma of the thyroid, has the potential to form amyloid fibrils and may be a valuable model for investigating the role of peptide–membrane interactions in β‐sheet and amyloid formation. Via a new model peptide system, bovine calcitonin, we found that the exposure of peptide to phospholipid membranes altered its structure relative to the structures formed in aqueous...

Abstract Calcium‐ and integrin‐binding protein (CIB) is a small EF‐hand calcium‐binding protein that is involved in hemostasis through its interaction with the αIIb cytoplasmic domain of integrinαIIbβ3. We have previously demonstrated that CIB lacks structural stability in the absence of divalent metal ions but that it acquires a well‐folded conformation upon addition of Ca2+ or Mg2+. Here, we have used fluorescence spectroscopy, NMR...

Abstract Hepatitis C virus uses an internal ribosome entry site (IRES) in the viral RNA to directly recruit human 40S ribosome subunits during cap‐independent translation initiation. Although IRES‐mediated translation initiation is not subject to many of the regulatory mechanisms that control cap‐dependent translation initiation, it is unknown whether other noncanonical protein factors are involved in this process. Thus, a global...

Abstract To develop a simple method for probing the physical state of surface adsorbed proteins, we adopted the force curve mode of an atomic force microscope (AFM) to extract information on the mechanical properties of surface immobilized bovine carbonic anhydrase II under native conditions and in the course of guanidinium chloride–induced denaturation. A progressive increase in the population of individually softened molecules was...

Abstract The presence of alanine (Ala) or acetyl serine (AcSer) instead of the normal Val residues at the N‐terminals of either the α‐ or the β‐subunits of human adult hemoglobin confers some novel and unexpected features on the protein. Mass spectrometric analysis confirmed that these substitutions were correct and that they were the only ones. Circular dichroism studies indicated no global protein conformational changes, and...

Abstract CFE88 is a conserved essential gene product from Streptococcus pneumoniae. This 227‐residue protein has minimal sequence similarity to proteins of known 3Dstructure. Sequence alignment models and computational protein threading studies suggest that CFE88 is a methyltransferase. Characterization of the conformation and function of CFE88 has been performed by using several techniques. Backbone atom and limited side‐chain atom NMR...

Abstract The aldo‐keto reductase (AKR) human type 3 3α‐hydroxysteroid dehydrogenase (h3α–HSD3, AKR1C2) plays a crucial role in the regulation of the intracellular concentrations of testosterone and 5α‐dihydrotestosterone (5α‐DHT), two steroids directly linked to the etiology and the progression of many prostate diseases and cancer. This enzyme also binds many structurally different molecules such as 4‐hydroxynonenal, polycyclic...

Abstract The X‐ray susceptibility of the lysine‐pyridoxal‐5′‐phosphate Schiff base in Bacillus alcalophilus phosphoserine aminotransferase has been investigated using crystallographic data collected at 100 K to 1.3 Å resolution, complemented by on‐line spectroscopic studies. X‐rays induce deprotonation of the internal aldimine, changes in the Schiff base conformation, displacement of the cofactor molecule, and disruption of the Schiff base...

Abstract Genome sequencing showed that two proteins in Mycobacterium tuberculosis H37Rv contain the metal binding motif (D/E)X2HX∼100(D/E)X2H characteristic of the soluble diiron enzyme superfamily. These putative acyl‐ACP desaturase genes desA1 and desA2 were cloned from genomic DNA and expressed in Escherichia coli BL21(DE3). DesA1 was found to be insoluble, but in contrast, DesA2 was a soluble protein amenable to biophysical characterization. Here, we...

Abstract The capsids of spherical viruses may contain from tens to hundreds of copies of the capsid protein(s). Despite their complexity, these particles assemble rapidly and with high fidelity. Subunit and capsid represent unique end states. However, the number of intermediate states in these reactions can be enormous—a situation analogous to the protein folding problem. Approaches to accurately model capsid assembly are still in...

Abstract Fibrillar collagens are the principal structural molecules of connective tissues. The assembly of collagen fibrils is regulated by quantitatively minor fibrillar collagens, types V and XI. A unique amino‐terminal propeptide domain of these collagens has been attributed this regulatory role. The structure of the amino terminal propeptide has yet to be determined. Low sequence similarity necessitated a secondary...

Page:   1 2 Next