Allosteric Modulation of the HIV-1 gp120-gp41 Association Site by Adjacent gp120 Variable Region 1 (V1) N-Glycans Linked to Neutralization Sensitivity

The HIV-1 gp120-gp41 complex, which mediates viral fusion and cellular entry, undergoes rapid evolution within its external glycan shield to enable escape from neutralizing antibody (NAb). Understanding how conserved protein determinants retain functionality in the context of such evolution is important for their evaluation and exploitation as potential drug and/ or vaccine targets. In this study, we examined how the conserved gp120-gp41 association site, formed by the N- and Cterminal segments of gp120 and the disulfide-bonded region (DSR) of gp41, adapts to glycan changes that are linked to neutralization sensitivity. To this end, a DSR mutant virus (K601D) with defective gp120-association was sequentially passaged in peripheral blood mononuclear cells to select suppressor mutations. We reasoned that the locations of suppressors point to structural elements that are functionally linked to the gp120-gp41 association site. In culture 1, gp120 association and viral replication was restored by loss of the conserved glycan at Asn136 in V1 (T138N mutation) inconjunction with the L494I substitution in C5 within the association site. In culture 2, replication was restored with deletion of the N139INN sequence, which ablates the overlapping Asn141-Asn142-Ser-Ser potential N-linked glycosylation sequons inV1, in conjunction with D601N in the DSR. The 136 and 142 glycan mutations appeared to exert their suppressive effects by altering the dependence of gp120-gp41 interactions on the DSR residues, Leu593, Trp596 and Lys601. The 136 and/or 142glycan mutations increased the sensitivity of HIV-1 pseudovirions to the glycan-dependent NAbs 2G12 and PG16, and also pooled IgG obtained from HIV-1-infected individuals. Thus adjacent V1 glycans allosterically modulate the distal gp120-gp41 association site. We propose that this represents a mechanism for functional adaptation of the gp120-gp41 association site to an evolving glycan shield in a setting of NAb selection

Methadone toxicity in infants: a report of two fatalities

Fatalities in infants resulting from methadone toxicity are rare within the United Kingdom. We report two cases of fatality attributed to methadone toxicity in infants aged 3A1/2 and 15 months of age, respectively. One of the two cases was also associated with diazepam ingestion. We discuss the difficulties with the interpretation of paediatric forensic toxicology and review the current literature related to methadone and diazepam toxicity in infants and older children

Methods for Producing Sporting Goods and Sporting Good

The present invention is directed to methods for producing at least a part of a sporting good, in particular a sports shoe. Furthermore, it is directed to a sporting good manufactured by such methods. According to one aspect of the invention, the method comprises the steps of: (a) depositing a first material into a mold and (b) vibrating the mold to modify the distribution of the first material in the mold

ANALYSIS OF ILLICIT DRUGS IN HUMAN BIOLOGICAL SAMPLES BY LC-MSn

There are several classes of illegal substances with different psychotropic effects. It is possible to select a biological matrix and a suitable analytical strategy depending on the aim of the analysis and/or on the availability of the sample or on which kind of information is needed. Liquid chromatography–mass spectrometry (LC-MS or LC-MS/MS) has provided a helpful tool in this field especially for hydrophilic, thermolabile, and nonvolatile analytes, which analysis is sometimes critical by gas chromatography–mass spectrometry (GC-MS). Specific guidelines or procedures have been adopted in order to assist the chemist and to direct him/her towards the practical applications, for which a new analytical method is being created, including measures of verification and external assessment. [...