0000000000003632
AUTHOR
Richard J. Lewis
Alhydrogel® adjuvant, ultrasonic dispersion and protein binding: A TEM and analytical study
Aluminium-based vaccine adjuvants have been in use since the 1920s. Aluminium hydroxide (alum) that is the chemical basis of Alhydrogel, a widely used adjuvant, is a colloid that binds proteins to the particular surface for efficient presentation to the immune system during the vaccination process. Using conventional TEM and cryo-TEM we have shown that Alhydrogel can be finely dispersed by ultrasonication of the aqueous suspension. Clusters of ultrasonicated aluminium hydroxide micro-fibre crystals have been produced (∼ 10-100 nm), that are significantly smaller than those present the untreated Alhydrogel (∼ 2-12 μm). However, even prolonged ultrasonication did not produce a homogenous susp…
A supramolecular complex in the environmental stress signalling pathway of Bacillus subtilis
SigmaB, an alternative sigma-factor of Bacillus subtilis, mediates the response of the cell to a variety of physical insults. Within the environmental stress signalling pathway RsbU, a protein phosphatase, is stimulated by its interaction with the protein kinase RsbT. In the absence of stress RsbT is expected to be trapped by an alternative binding partner, RsbS. Here, we have demonstrated that RsbS alone cannot act as an alternative partner for RsbT, but instead requires the presence of RsbR to create a high molecular mass RsbR:RsbS complex (approximately 1 MDa) able to capture RsbT. In this complex the phosphorylation state of RsbS, and not that of RsbR, controlled the binding to RsbT, wh…
α-Conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors
The Xenopus laevis oocyte expression system was used to determine the activities of alpha-conotoxins EpI and the ribbon isomer of AuIB, on defined nicotinic acetylcholine receptors (nAChRs). In contrast to previous findings on intracardiac ganglion neurones, alpha-EpI showed no significant activity on oocyte-expressed alpha3beta4 and alpha3beta2 nAChRs but blocked the alpha7 nAChR with an IC50 value of 30 nM. A similar IC50 value (103 nM) was obtained on the alpha7/5HT3 chimeric receptor stably expressed in mammalian cells. Ribbon AuIB maintained its selectivity on oocyte-expressed alpha3beta4 receptors but unlike in native cells, where it was 10-fold more potent than native alpha-AuIB, had…
Corrigendum to: α-Conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors (FEBS 27779)
Corrigendum to: K-Conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors (FEBS 27779) [FEBS Letters 554 (2003) 219^223]C Annette Nickea;1, Marek Samochockib, Marion L. Loughnana, Paramjit S. Bansala, Alfred Maelickeb, Richard J. Lewisa; aInstitute for Molecular Bioscience, University of Queensland, Brisbane, Qld. 4072, Australia bInstitute for Physiological Chemistry and Pathobiochemistry, University of Mainz, D-55099 Mainz, Germany First published online 24 December 2003
The collagen type I segment long spacing (SLS) and fibrillar forms: Formation by ATP and sulphonated diazo dyes.
The collagen type I segment long spacing (SLS) crystallite is a well-ordered rod-like molecular aggregate, ∼300nm in length, which is produced in vitro under mildly acidic conditions (pH 2.5-3.5) in the presence of 1mM ATP. The formation of the SLS crystallite amplifies the inherent linear structural features of individual collagen heterotrimers, due to the punctate linear distribution and summation of the bulkier amino acid side chains along the length of individual collagen heterotrimers. This can be correlated structurally with the 67nm D-banded collagen fibril that is found in vivo, and formed in vitro. Although first described many years ago, the range of conditions required for ATP-in…