First studies on tumor associated carbonic anhydrases IX and XII monoclonal antibodies conjugated to small molecule inhibitors.

We report for the first time Antibody-Drug-Conjugates (ADCs) containing human (h) Carbonic Anhydrase (CA; EC 4.2.1.1) directed Monoclonal Antibodies (MAbs) linked to low molecular weight inhibitors of the same enzymes by means of hydrophilic peptide spacers. In agreement with the incorporated CA directed MAb fragments, in vitro inhibition data of the obtained ADCs showed sub-nanomolar KI values for the tumour associated CAs IX and XII which were up to 10-fold more potent when compared to the corresponding unconjugated MAbs. In addition, the introduction of the CA inhibitor (CAI) benzenesulfonamide allowed the ADCs to potently inhibit the housekeeping tumoral off-target human CA II isoform. Such results are supporting the definition of an unprecedented reported class of ADCs able to hit simultaneously multiple hCAs physiologically cooperative in maintaining altered cellular metabolic pathways, and therefore ideal for the treatment of chronic diseases such as cancers and inflammation diseases.

Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC)-Mediated Macrocyclization of Peptides: Impact on Conformation and Biological Activity.

The long-lasting impetus to design novel modes of macrocyclization, and their implementation into a wide range of bioactive peptides, originates from their contributions to the restriction of conformational space and the stabilization of preferential bioactive conformations that support higher efficacy and binding affinity to cognate macromolecular targets, improved specificity and lowering susceptibility to enzymatic degradation processes. Introducing CuI-catalyzed azide-alkyne cycloaddition (CuAAC), a prototypical click reaction, to the field of peptide sciences as a bio-orthogonal reaction that generates a disubstituted-[1,2,3]triazol-1-yl moiety as a pseudopeptidic bond that is peptidomimetic in nature, paved the way to its widespread application as a new and promising mode of macrocyclization. This review presents the state-of-art of CuAAC-mediated macrocyclization as it applies to an expansive range of bioactive peptides and explores the relationship among the structural diversity of CuAACmediated cyclizations, biological activities and conformations.

Antibodies from multiple sclerosis patients preferentially recognize hyperglucosylated adhesin of non-typeable Haemophilus influenzae.

In autoimmune diseases, there have been proposals that exogenous "molecular triggers", i.e., specific 'non-self antigens' accompanying infectious agents, might disrupt control of the adaptive immune system resulting in serious pathologies. The etiology of multiple sclerosis (MS) remains unclear. However, epidemiologic data suggest that exposure to infectious agents may be associated with increased MS risk and progression may be linked to exogenous, bacterially-derived, antigenic molecules, mimicking mammalian cell surface glycoconjugates triggering autoimmune responses. Previously, antibodies specific to a gluco-asparagine (N-Glc) glycopeptide, CSF114(N-Glc), were identified in sera of an MS patient subpopulation. Since the human glycoproteome repertoire lacks this uniquely modified amino acid, we turned our attention to bacteria, i.e., Haemophilus influenzae, expressing cell-surface adhesins including N-Glc, to establish a connection between H. influenzae infection and MS. We exploited the biosynthetic machinery from the opportunistic pathogen H. influenzae (and the homologous enzymes from A. pleuropneumoniae) to produce a unique set of defined glucosylated adhesin proteins. Interestingly we revealed that a hyperglucosylated protein domain, based on the cell-surface adhesin HMW1A, is preferentially recognized by antibodies from sera of an MS patient subpopulation. In conclusion the hyperglucosylated adhesin is the first example of an N-glucosylated native antigen that can be considered a relevant candidate for triggering pathogenic antibodies in MS.

Di-(2-ethylhexyl) phthalate metabolites in urine show age-related changes and associations with adiposity and parameters of insulin sensitivity in childhood.

OBJECTIVES: Phthalates might be implicated with obesity and insulin sensitivity. We evaluated the levels of primary and secondary metabolites of Di-(2-ethylhexyl) phthalate (DEHP) in urine in obese and normal-weight subjects both before and during puberty, and investigated their relationships with auxological parameters and indexes of insulin sensitivity. DESIGN AND METHODS: DEHP metabolites (MEHP, 6-OH-MEHP, 5-oxo-MEHP, 5-OH-MEHP, and 5-CX-MEHP), were measured in urine by RP-HPLC-ESI-MS. Traditional statistical analysis and a data mining analysis using the Auto-CM analysis were able to offer an insight into the complex biological connections between the studied variables. RESULTS: The data showed changes in DEHP metabolites in urine related with obesity, puberty, and presence of insulin resistance. Changes in urine metabolites were related with age, height and weight, waist circumference and waist to height ratio, thus to fat distribution. In addition, clear relationships in both obese and normal-weight subjects were detected among MEHP, its products of oxidation and measurements of insulin sensitivity. CONCLUSION: It remains to be elucidated whether exposure to phthalates per se is actually the risk factor or if the ability of the body to metabolize phthalates is actually the key point. Further studies that span from conception to elderly subjects besides further understanding of DEHP metabolism are warranted to clarify these aspects.

1,4-disubstituted-[1,2,3]triazolyl-containing analogues of MT-II: design, synthesis, conformational analysis, and biological activity.

Side chain-to-side chain cyclizations represent a strategy to select a family of bioactive conformations by reducing the entropy and enhancing the stabilization of functional ligand-induced receptor conformations. This structural manipulation contributes to increased target specificity, enhanced biological potency, improved pharmacokinetic properties, increased functional potency, and lowered metabolic susceptibility. The Cu(I)-catalyzed azide-alkyne 1,3-dipolar Huisgen's cycloaddition, the prototypic click reaction, presents a promising opportunity to develop a new paradigm for an orthogonal bioorganic and intramolecular side chain-to-side chain cyclization. In fact, the proteolytic stable 1,4- or 4,1-disubstituted [1,2,3]triazolyl moiety is isosteric with the peptide bond and can function as a surrogate of the classical side chain-to-side chain lactam forming bridge. Herein we report the design, synthesis, conformational analysis, and functional biological activity of a series of i-to-i+5 1,4- and 4,1-disubstituted [1,2,3]triazole-bridged cyclopeptides derived from MT-II, the homodetic Asp(5) to Lys(10) side chain-to-side chain bridged heptapeptide, an extensively studied agonist of melanocortin receptors.

Solvent independent conformational propensities of [1,2,3]triazolyl-bridged parathyroid hormone-related peptide-derived cyclo-nonapeptide analogues.

The recently introduced Cu(I)-catalyzed azide-alkyne 1,3-dipolar Huisgen cycloaddition as a prototypic "click chemistry reaction" presented an opportunity for introducing the 1,4-disubstituted-[1,2,3]triazolyl moiety as a new isostere for peptide bonds in the backbone. Previous study in our lab focused on the synthesis of a model i-to-i+4 side chain-to-side chain 1,4- and 4,1-disubstituted-[1,2,3]triazolyl-bridged cyclo-nonapeptide I (Scheme 1) as analogues of its structurally related helical i-to-i+4 lactam-bridged cyclo-nonapeptide [Lys¹³ (&¹), Asp¹7 (&²)]parathyroid hormone related peptide (PTHrP)(11-19)NH2 (1) a truncated version of the α-helical and potent parathyroid hormone receptor 1 agonist [Lys¹³ (&¹), Asp¹7 (&²)]PTHrP(1-34)NH2, (2,3) N(α) -Ac-Lys-Gly-Lys(&¹)-Ser-Ile-Gln-Asp(&²)-Leu-Arg-NH2]. Systematic [1,2,3]triazolyl-containing bridge structure-conformation relationship studies in hexafluoroacetone/water mixture included incorporation of bridges varied in size and position and orientation of the triazolyl ring within the bridge. These studies revealed that the size of methylene bridge flanking triazolyl moiety is critical to reproduce in the heterodetic cyclo-nonapeptides. The conformational features of the analogues cyclo-nonapeptide in which Lys¹³ and Asp¹7 are bridged by the isosteric lactam. Here, we extend our conformational analysis to dimethyl sulfoxide/water mixture in an effort to characterize inherent conformational properties of the heterodetic cyclopeptides that are solvent independent. Our present study shows that the physicochemical properties of the structure-supporting solvent cannot override the effect of the size of methylene bridge to form helical mimetic structures. Moreover, we prove that [1,2,3]triazolyl ring is not a simple bioisostere of lactam bond, but it affects the secondary structure of the peptide, in relation to its positioning orientation.

Di-(2-ethylhexyl) phthalate and autism spectrum disorders.

ASDs (autism spectrum disorders) are a complex group of neurodevelopment disorders, still poorly understood, steadily rising in frequency and treatment refractory. Extensive research has been so far unable to explain the aetiology of this condition, whereas a growing body of evidence suggests the involvement of environmental factors. Phthalates, given their extensive use and their persistence, are ubiquitous environmental contaminants. They are EDs (endocrine disruptors) suspected to interfere with neurodevelopment. Therefore they represent interesting candidate risk factors for ASD pathogenesis. The aim of this study was to evaluate the levels of the primary and secondary metabolites of DEHP [di-(2-ethylhexyl) phthalate] in children with ASD. A total of 48 children with ASD (male: 36, female: 12; mean age: 11 ± 5 years) and age- and sex-comparable 45 HCs (healthy controls; male: 25, female: 20; mean age: 12 ± 5 years) were enrolled. A diagnostic methodology, based on the determination of urinary concentrations of DEHP metabolites by HPLC-ESI-MS (HPLC electrospray ionization MS), was applied to urine spot samples. MEHP [mono-(2-ethylhexenyl) 1,2-benzenedicarboxylate], 6-OH-MEHP [mono-(2-ethyl-6-hydroxyhexyl) 1,2-benzenedicarboxylate], 5-OH-MEHP [mono-(2-ethyl-5-hydroxyhexyl) 1,2-benzenedicarboxylate] and 5-oxo-MEHP [mono-(2-ethyl-5-oxohexyl) 1,2-benzenedicarboxylate] were measured and compared with unequivocally characterized, pure synthetic compounds (>98%) taken as standard. In ASD patients, significant increase in 5-OH-MEHP (52.1%, median 0.18) and 5-oxo-MEHP (46.0%, median 0.096) urinary concentrations were detected, with a significant positive correlation between 5-OH-MEHP and 5-oxo-MEHP (rs = 0.668, P<0.0001). The fully oxidized form 5-oxo-MEHP showed 91.1% specificity in identifying patients with ASDs. Our findings demonstrate for the first time an association between phthalates exposure and ASDs, thus suggesting a previously unrecognized role for these ubiquitous environmental contaminants in the pathogenesis of autism.

Conventional and microwave-assisted SPPS approach: a comparative synthesis of PTHrP(1-34)NH(2).

Attracted by the possibility to optimize time and yield of the synthesis of difficult peptide sequences by MW irradiation, we compared Fmoc/tBu MW-assisted SPPS of 1-34 N-terminal fragment of parathyroid hormone-related peptide (PTHrP) with its conventional SPPS carried out at RT. MWs were applied in both coupling and deprotection steps of SPPS protocol. During the stepwise elongation of the resin-bound peptide, monitoring was conducted by performing MW-assisted mini-cleavages and analyzing them by UPLC-ESI-MS. Identification of some deletion sequences was helpful to recognize critical couplings and as such helped to guide the introduction of MW irradiations to these stages.