β-Mannosidase from Cellulomonas fimi: Immobilization Study and Application in the β-Mannoside Synthesis

The β-d-mannopyranoside linkage is found in a number of biological structures, in particular, in the core trisaccharide of N-linked glycoproteins, as well as within the antigenic polysaccharides of Salmonella, yeasts, and glycolipids. The construction of this glycosydic bond by chemical approach is very challenging and requires cumbersome protection and activation steps prior to glycosylation. In this context, β-mannosidase from Cellulomonas fimi (Cf-β-Man) was immobilized for the first time, and it was employed in the synthesis of β-mannosides. Cf-β-Man immobilized on IDA-Co2+-agarose allows the synthesis of the disaccharide, cyanomethyl β-d-mannopyranosyl-(1→6)-2-acetamido-2-deoxy-1-thio-β-d-glucopyranoside, with a higher conversion compared to the soluble enzyme (20% vs. 5%) after 6 h under best conditions. This explorative work opens new scenarios concerning the design of engineered Cf-β-Man mutants and their immobilization in order to obtain a robust and recyclable biocatalyst for applications in chemoenzymatic glycan synthesis

Body ownership increases the interference between observed and executed movements

When we successfully achieve willed actions, the feeling that our moving body parts belong to the self (i.e., body ownership) is barely required. However, how and to what extent the awareness of our own body contributes to the neurocognitive processes subserving actions is still debated. Here we capitalized on immersive virtual reality in order to examine whether and how body ownership influences motor performance (and, secondly, if it modulates the feeling of voluntariness). Healthy participants saw a virtual body either from a first or a third person perspective. In both conditions, they had to draw continuously straight vertical lines while seeing the virtual arm doing the same action (i.e., drawing lines) or deviating from them (i.e., drawing ellipses). Results showed that when there was a mismatch between the intended and the seen movements (i.e., participants had to draw lines but the avatar drew ellipses), motor performance was strongly 'attracted' towards the seen (rather than the performed) movement when the avatar's body part was perceived as own (i.e., first person perspective). In support of previous studies, here we provide direct behavioral evidence that the feeling of body ownership modulates the interference of seen movements to the performed movements

SIAMOC position paper on gait analysis in clinical practice: General requirements, methods and appropriateness. Results of an Italian consensus conference

Gait analysis is recognized as a useful assessment tool in the field of human movement research. However, doubts remain on its real effectiveness as a clinical tool, i.e. on its capability to change the diagnostic-therapeutic practice. In particular, the conditions in which evidence of a favorable cost-benefit ratio is found and the methodology for properly conducting and interpreting the exam are not identified clearly. To provide guidelines for the use of Gait Analysis in the context of rehabilitation medicine, SIAMOC (the Italian Society of Clinical Movement Analysis) promoted a National Consensus Conference which was held in Bologna on September 14th, 2013. The resulting recommendations were the result of a three-stage process entailing i) the preparation of working documents on specific open issues, ii) the holding of the consensus meeting, and iii) the drafting of consensus statements by an external Jury. The statements were formulated based on scientific evidence or experts' opinion, when the quality/quantity of the relevant literature was deemed insufficient. The aim of this work is to disseminate the consensus statements. These are divided into 13 questions grouped in three areas of interest: 1) General requirements and management, 2) Methodological and instrumental issues, and 3) Scientific evidence and clinical appropriateness. SIAMOC hopes that this document will contribute to improve clinical practice and help promoting further research in the field

2-O-Acetyl-3,4,5,6-tetra-O-benzyl-D-myo-inosityl diphenylphosphate: a new useful intermediate to inositol phosphate and phospholipids

Inositol phosphates and inositol phospholipids are ubiquitous in biochemistry and play a central role in cell signaling and regulation events. For this reason, their synthesis has attracted widespread interest. This paper describes the preparation of a new optically active inositol phosphate derivative, 2-O-acetyl-3,4,5,6-tetra-O-benzyl-D-myo-inosityl diphenylphosphate (6), and its characterization by spectroscopic methods. Compound (6) represents a useful intermediate for the preparation of inositol phosphate and phospholipids, in particular of glycerophosphoinositol (GPI), a natural anti-inflammatory agent

Unveiling the role of the ring size in the sugar-based tensides surfactancy by interfacial studies and molecular dynamics

Sugar Fatty Acid Esters (SFAEs) are a class of biosurfactants that are gaining growing attention due to their excellent emulsifying, stabilizing and detergency properties; moreover, they show several advantages over their petroleum-based counterparts being non-toxic, fully biodegradable and environmentally friendly. Herein, a series of alkyl 6-O-palmitoyl-D-glucosides were enzymatically synthesized by reacting alkyl D-glucoside isomeric mixtures with molten palmitic acid in an easily scalable solvent-free system. Couples of anomers, namely pyranosides-(Py) and furanosides-based compounds (Fu), were isolated through flash column chromatography. Investigation of interfacial tension (IFT), water-in-sunflower oil (W/O) emulsifying capability and subsequent stability over time by turbidimetric and confocal microscope analyses indicated strong differences in their physico-chemical properties, with Py-derivatives showing better surfactancy with respect to that of Fu ones. Furthermore, computational studies were performed aiming at both unravelling the role of ring size (Py vs Fu) in the surfactant mixtures and at evaluating the water-in-oil emulsion formation and stabilization

Bio-based emulsifiers through enzymatic hydrolysis of a soy protein isolate

Protein-based surfactants are gaining interest in several industrial sectors, due to their low-cost and biodegradability. Their properties make them a valid bio-based alternative to petrochemical-based tensides, thus reducing environmental and health concerns. To enhance their techno-functional properties, protein structure must be modified. Compared to chemical methods, enzymatic hydrolysis offers an industrially viable and sustainable approach for this purpose. Particularly, by adjusting enzymatic hydrolysis parameters (type of enzyme, incubation time, temperature and pH), the surfactancy of proteins can be substantially altered, broadening both the application range and the conventional emulsifiers choice. In this study, a commercial soy protein isolate (SPI) was hydrolysed through a biocatalytic approach, using Alcalase® 2.4L FG and Protamex® as enzymatic preparations, at different incubation time (15, 120, 360 min). The resulting Soy Protein Hydrolysates (SPHs) were characterised by ultrafiltration with molecular weight cut-off membranes of 10, 5, and 1 kDa. Then, the emulsifying properties of the prepared SPHs were investigated by interfacial tension (IFT) studies. The two hydrolysates, that achieved the greatest IFT reduction, were tested as emulsifiers in simple peanut oil-in-water (O/W) emulsions, prepared with a sonicator device. Their stability over time was evaluated by turbidimetry, emulsion stability index, confocal microscopy images and dynamic light scattering analyses. Protein secondary structures/emulsifying capability relationship was proposed based on circular dichroism (CD) analyses. Furthermore, for potential industrial applications, more complex O/W emulsions (including rheological modifier, solubilizing agent, antioxidants, and buffers) were also formulated using a rotor-stator. Finally, the stabilityand rheological behavior of these complex emulsions were thoroughly examined

Emulsifying properties of sugar-based surfactants prepared by chemoenzymatic synthesis

Sugar Fatty Acid Esters (SFAEs) are a class of non-ionic surfactants that can be synthesized from inexpensive natural resources. Depending on carbon chain length and nature of the sugar head group, SFAEs cover a wide range of hydrophilic–lipophilic balance (HLB) values, which result in tunable tenside properties and in turn relevant for a wide variety of industrial applications. Three sugar-based surfactants (6-O-lauroyl-, 6-O-palmitoyl- and 6-O-stearoyl-1-O-butyl glucopyranosides) have been prepared by a lipase-catalyzed esterification of isomeric mixture of n-butyl glucosides. Specifically, their interfacial features together with W/O emulsifying properties and stability over time have been finely evaluated (interfacial tension (IFT) values, W/O emulsion turbidity water droplet size distribution, first order kinetic constants of de-emulsification)