Identification of NCAM-binding peptides promoting neurite outgrowth via a heterotrimeric G-protein-coupled pathway.

A combinatorial library of undecapeptides was produced and utilized for the isolation of peptide binding to the fibronectin type 3 modules (F3I-F3II) of the neural cell adhesion molecule (NCAM). The isolated peptides were sequenced and produced as dendrimers. Two of the peptides (denoted ENFIN2 and ENFIN11) were confirmed to bind to F3I-F3II of NCAM by surface plasmon resonance.

Mechanisms of inactivation of HSV-2 during storage in frozen and lyophilized forms.

The structural integrity of herpes simplex virus 2 (HSV-2) during freezing, thawing, and lyophilization has been studied using scanning and transmission electron microscopy. Viral particles should be thawed quickly from -80 to 37 degrees C to avoid artifacts of thawing. To avoid freezing damage, the virus should be rapidly frozen (>20 K s(-1)) rather than slowly frozen as occurs on the shelf of a lyophilizer (<1 K s(-1)).

Interaction between an amantadine analogue and the transmembrane portion of the influenza A M2 protein in liposomes probed by 1H NMR spectroscopy of the ligand.

1H NMR spectroscopy of a fluoroamantadine ligand was used to probe the pH dependence of binding to the transmembrane peptide fragment of the influenza A M2 proton channel (M2TM) incorporated into 1,2-dimyristoyl-sn-glycero-3-phosphocholine liposomes. Above pH 7.5, when M2TM bound the ligand, fluoroamantadine resonances became too broad to be detected.

Effect of freezing rates and excipients on the infectivity of a live viral vaccine during lyophilization.

Lyophilization is the most popular method for achieving improved stability of labile biopharmaceuticals, but a significant fraction of product activity can be lost during processing due to stresses that occur in both the freezing and the drying stages. The effect of the freezing rate on the recovery of herpes simplex virus 2 (HSV-2) infectivity in the presence of varying concentrations of cryoprotectant excipients is reported here. The freezing conditions investigated were shelf cooling (223 K), quenching into slush nitrogen (SN2), and plunging into melting propane cooled in liquid nitrogen (LN2).

Hydrogen/deuterium exchange of hydrophobic peptides in model membranes by electrospray ionization mass spectrometry.

We demonstrate here that the hydrogen/deuterium solvent exchange (HDX) properties of the transmembrane fragment of the M2 protein of Influenza A (M2-TM) incorporated into lipid vesicles or detergent micelles can be studied with straightforward electrospray (ESI) and nanospray mass spectrometry (MS) configurations provided that key factors, including sample preparation techniques, are optimized. Small unilamellar vesicle preparations were obtained by solubilizing dimyristoyl phosphatidylcholine (DMPC) and the M2-TM peptide in aqueous solution with n-octyl-beta-D-glycopyranoside, followed by dialysis to remove the detergent. Electron microscopy experiments revealed that subsequent concentration by centrifugation introduced large multilamellar aggregates that were not compatible with ESI-MS.