45 research outputs found
The primary structure of the flavoprotein D-aspartate oxidase from beef kidney.
The complete primary structure of the peroxisomal flavoenzyme D-aspartate oxidase from beef kidney has been determined by analyses of the peptides obtained through fragmentation of the carboxymethylated protein with trypsin, CNBr, heptafluorobutyric acid/CNBr and Staphylococcus aureus V8 protease. The protein consists of a single polypeptide of 338 residues, accounting for a M(r) of 37,305 for the apoprotein. A form of the enzyme lacking Lys-338 and therefore ending with Pro-337 has been detected. The N-terminal residue is blocked. Seven cysteines and no disulfide bridges are present. Residue 228 can be either Ile or Val. Thus, D-aspartate oxidase presents two types of heterogeneity in the polypeptide chain in addition to the one already described concerning the possible content of FAD or 6-hydroxyflavin adenine dinucleotide. Comparison of the primary structure of D-aspartate oxidase with other known sequences reveals that D-aspartate oxidase is homologous with D-amino acid oxidase (another flavo-oxidase) and does not present significant sequence similarities with any other protein, including flavoenzymes
Limited proteolysis of a disulfide-linked apoA-I dimer in reconstituted HDL.
The apolipoprotein A-I Milano (apoA-I M ) is a mo- lecular variant of apoA-I characterized by the Arg 173 → Cys substitution, leading to the formation of homodimers A-I M / A-I M. Upon interaction with palmitoyloleoylphosphatidyl- choline, A-I M /A-I M forms only two species of reconstituted HDL (rHDL) particles, with diameters of 7.8 and 12.5 nm. We used limited proteolysis to analyze the conformation of A-I M /A-I M in the two rHDL particles, in comparison with that of apoA-I in rHDL of similar size. ApoA-I in the small, 7.8-nm rHDL is degraded to a greater extent (50% after 6 h) than in the large rHDL ( � 10% degraded after 6 h). The pro- tease susceptibility of A-I M /A-I M in small and large rHDL is instead remarkably the same, with A-I M /A-I M being much more sensitive to proteolytic digestion (50% degraded after 10 min) than apoA-I. The identification of the proteolytic fragments by immunoblotting, N-terminal sequencing, and molecular mass determination, shows that the N-terminus of both proteins is resistant to proteolysis, with six cleavage sites located in the central and carboxy-terminal portions of the molecules. Cleavage in the middle of apoA-I occurs at dis- tinct sites in 7.8-nm (Lys 118 ) and 12.7-nm (Arg 123 ) rHDL, in- dicating a different conformation in small and large rHDL particles. The A-I M /A-I M instead adopts a unique and identi- cal conformation in small and large rHDL, with the carboxy- terminal portion of the molecule being remarkably more ac- cessible to the proteases than in apoA-I. This suggests the presence of a novel carboxy-terminal domain in A-I M /A-I M , not organized in a compact structure and not shared by wild-type apoA-I, which may account for the unique functional proper- ties of A-I M /A-I M. —Calabresi, L., G. Tedeschi, C. Treu, S. Ron- chi, D. Galbiati, S. Airoldi, C. R. Sirtori, Y. Marcel, and G. Franceschini. Limited proteolysis of a disulfide-linked apoA-I dimer in reconstituted HDL. J. Lipid Res. 2001. 42: 935-942
OBTENÇÃO DE BIODIESEL ETÍLICO DE BANHA SUÍNA E ÓLEO RESIDUAL DE FRITURA POR CATÁLISE HOMOGÊNEA COM GLICERÓXIDO DE SÓDIO
principal custo de produção do biodiesel são as matérias-primas. Deste modo, fontes graxas como óleos e gorduras residuais têm atraído a atenção de produtores debiodiesel devido ao seu baixo custo. Com relação aos catalisadores, o emprego de derivados da glicerina também aparecem como uma alternativa para aumentar acompetitividade da cadeia produtiva do biodiesel. Neste trabalho, o objetivo foi avaliar o uso de gliceróxido de sódio na transesterificação etílica de banha suína e óleo residual de fritura. O catalisador foi empregado a 2,0% em massa sobre uma razão molar de EtOH/triglicerídeo de 12:1 à 50 ºC em 1 h de reação, fornecendo conversões de biodieseis de banha suína a 97,1% e óleo residual de fritura a 93,9%. Os resultados obtidos demonstraram o potencial catalítico do gliceróxido de sódio na transesterificação destes triglicerídeos com o EtOH
OBTENÇÃO DE BIODIESEL ETÍLICO DE BANHA SUÍNA E ÓLEO RESIDUAL DE FRITURA POR CATÁLISE HOMOGÊNEA COM GLICERÓXIDO DE SÓDIO
Fontes graxas como óleos e gorduras residuais têm atraído a atenção de produtoresde biodiesel devido ao seu baixo custo. O emprego de derivados da glicerinatambém é uma alternativa para aumentar a competitividade da cadeia produtiva dobiodiesel. Neste trabalho, avaliamos o uso de gliceróxido de sódio natransesterificação etílica de banha suína e óleo residual de fritura. O catalisador foiempregado a 2,0% em massa sobre uma razão molar de EtOH/triglicerídeo de 12:1à 50 ºC em 1 h de reação, fornecendo conversões de biodieseis de banha suína a97,1% e óleo residual de fritura a 93,9%
Junctional Nevus and Early Melanoma on Sun-Damaged Skin of the Head/Neck: A Clinico-Pathologic Challenge
Introduction: Melanoma on the head/neck area can show subtle clinical, dermoscopic and histologic features at early stages, being difficult to differentiate from junctional nevi.
Objectives: This case series aims to raise awareness on the topic of misdiagnosis of early lentigo maligna as junctional nevi.
Methods: From the databases of three pigmented lesion clinics in Italy, Australia, and France, we retrieved all cases of lesions of the head/neck area with an initial histopathologic diagnosis of junctional nevus (JN) or dysplastic junctional nevus (DJN) which subsequently recurred and were ultimately diagnosed as melanoma. Moreover, we also retrieved those cases with an initial diagnosis of JN/DJN made on a partial biopsy that were diagnosed as melanoma after complete surgical removal.
Results: Here we report 14 cases in which the initial histologic diagnosis was junctional nevus or dysplastic junctional nevus. The lesions recurred over time with a final diagnosis of lentigo maligna.
Conclusions: Clinicians should critically question a given histologic diagnosis of junctional or dysplastic junctional nevus on the head/neck area if the clinical or dermoscopic features are discordant. Clinico-pathologic correlation is the best way to increase diagnostic accuracy and optimize management for the patient
Social cognition in people with schizophrenia: A cluster-analytic approach
Background The study aimed to subtype patients with schizophrenia on the basis of social cognition (SC), and to identify cut-offs that best discriminate among subtypes in 809 out-patients recruited in the context of the Italian Network for Research on Psychoses. Method A two-step cluster analysis of The Awareness of Social Inference Test (TASIT), the Facial Emotion Identification Test and Mayer-Salovey-Caruso Emotional Intelligence Test scores was performed. Classification and regression tree analysis was used to identify the cut-offs of variables that best discriminated among clusters. Results We identified three clusters, characterized by unimpaired (42%), impaired (50.4%) and very impaired (7.5%) SC. Three theory-of-mind domains were more important for the cluster definition as compared with emotion perception and emotional intelligence. Patients more able to understand simple sarcasm (14 for TASIT-SS) were very likely to belong to the unimpaired SC cluster. Compared with patients in the impaired SC cluster, those in the very impaired SC cluster performed significantly worse in lie scenes (TASIT-LI <10), but not in simple sarcasm. Moreover, functioning, neurocognition, disorganization and SC had a linear relationship across the three clusters, while positive symptoms were significantly lower in patients with unimpaired SC as compared with patients with impaired and very impaired SC. On the other hand, negative symptoms were highest in patients with impaired levels of SC. Conclusions If replicated, the identification of such subtypes in clinical practice may help in tailoring rehabilitation efforts to the person's strengths to gain more benefit to the person
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
I volgarizzamenti italiani dell' "Histoire ancienne". La sezione tebana
Nel saggio si dà l’edizione sinottica, relativamente alla sezione Tebana, dei volgarizzamenti
toscani noti dell’Histoire ancienne jusqu’à César e di quello recentemente rinvenuto attribuito
a Zucchero Bencivenni. L’edizione è seguita da un commento dei passi più significativi per
affinità o divergenze: la conclusione cui si giunge è che si tratti di un unico volgarizzamento e
che Bencivenni lavori su una traduzione già esistente, operando una sistematica collazione
con la fonte frances