Biomedical subjects

Carlo Caporale

Publications and source records attributed to Carlo Caporale.

6 recordsLinked to original sources

PubMed2006

Cloning and structural analysis of a haemocyanin from the Stonefly Perla grandis.

We characterized two subunits of a putative haemocyanin from the stonefly species Perla grandis. In particular, we cloned and sequenced the corresponding cDNAs and studied their expression in different insect stages. Moreover, using the deduced amino acid sequences, homology studies were performed both on their primary and tertiary structures. 3-D molecular modelling data showed that the residues involved in the oxygen transport and subunits contacts were located in spatial positions preserving the functionality of the molecule. Despite it was paradigmatically affirmed that insects do not have respiratory proteins, our data suggest that the haemocyanin could be involved in the respiratory mechanisms of P. grandis. As far as we know, this is the first haemocyanin 3-D structure described and analyzed in insects.

Amino Acid Sequence↗

PubMed2006

Molecular and functional analysis of new members of the wheat PR4 gene family.

Five new genes belonging to the pathogenesis-related (PR) 4 family have been cloned and characterised in Triticum aestivum. Two full-length genes, named wPR4e and wPR4f-b, were isolated by library screening, demonstrating the presence of a small intron only in wPR4f-b. Two other PR4 genes (wPR4f-a and wPR4f-c) were isolated by PCR, showing very high sequence identity with wPR4f-b and constituting a new sub-family. Transcription start analysis was performed by RLM-RACE, leading to the isolation of a fifth gene, named wPR4g, that is highly homologous to wPR4e; both encode putative vacuolar PR4 proteins (Wheatwin7 and Wheatwin5, respectively). wPR4e and wPR4f sub-family genes are induced by F. culmorum infection, by chemicals that lead to systemic acquired resistance and by wounding, showing different spatial and temporal induction pathways. In silico analysis of the 5' untranslated regions of wPR4e and wPR4f-b revealed the presence of several abiotic and biotic stress-responsive elements. wPR4e and wPR4f-b putative promoters were fused to the beta-glucuronidase (GUS) reporter gene, and transient and stable expression assays demonstrated that both are able to drive expression of GUS. Characterisation of these new PR4 genes and particularly of their 5' untranslated regions, as well as the determination of their expression patterns, will contribute to our understanding of the responsiveness of this gene family to various stress conditions and of its role in plant defence.

Amino Acid Sequence↗

PubMed2005

CysMap and CysJoin: database and tools for protein disulphides localisation.

We have developed a computer program able to make user-customised databases derived from the public PIR non-redundant reference protein database. When the database of interest has been created, the user will generate the map of all the possible linear peptides containing one and two cysteines for each protein and combine them to calculate the mass of all the possible clusters of linear peptides linked by a disulphide bridge with a cysteine pair. It is also possible to create selected maps corresponding to peptides formed by the action of specific proteases. In this way, mass spectrometric data obtained from the hydrolysis of proteins of unknown sequence can be related to that contained in the database for quick disulphide assignment and protein identification. To confirm signal attribution, the program will also furnish the expected mass of cluster peptides after performing a cycle of Edman degradation. The utility of the program is discussed and examples of application are given.

Amino Acid Sequence↗

PubMed2004

Wheat pathogenesis-related proteins of class 4 have ribonuclease activity.

We have demonstrated that wheatwin1, a wheat pathogenesis-related protein of class 4 (PR4), has ribonuclease activity. Both native and recombinant proteins hydrolyse RNA from wheat coleoptils and have antifungal activity. Sepharose-bound wheatwin1 is able to interact with either wheat or Fusarium culmorum RNA. 3D modelling studies showed that, like ribonucleases A and T1, the action mechanism should involve two His residues, an Arg residue and an Asp residue.

Amino Acid Sequence↗

PubMed2004

Structural properties of the protein SV-IV.

We have investigated the molecular mechanisms that produce different structural and functional behavior in the monomeric and trimeric forms of seminal vesicle protein no. 4, a protein with immunomodulatory, anti-inflammatory, and procoagulant activity secreted from the rat seminal vesicle epithelium. The monomeric and trimeric forms were characterized in solution by CD. Details of the self-association process and structural changes that accompany aggregation were investigated by different experimental approaches: trypsin proteolysis, sequence analysis, chemical modification, and computer modeling. The self-association process induces conformational change mainly in the 1-70 region, which appears to be without secondary structure in the monomer but contains alpha-helix in the trimer. In vivo, proteolysis of seminal vesicle protein no. 4 generates active peptides and this is affected by the monomer/trimer state, which is regulated by the concentration of the protein. The information obtained shows how conformational changes between the monomeric and trimeric forms represent a crucial aspect of activity modulation.

Animals↗

PubMed2003

Comparing the modeled structures of PR-4 proteins from wheat.

We have constructed three-dimensional models of four pathogenesis-related (PR) proteins from wheat (wheatwins) belonging to the PR-4 family. All the models were based on the knowledge of the tertiary structure of barwin, a highly homologous protein from barley. Wheatwin1 and wheatwin2 differ in two amino acid residues (positions 62 and 68) out of 125. Wheatwin4 differs from wheatwin2 in one residue at position 78, while wheatwin3 differs from wheatwin1 in one residue at position 88. The global folding and the secondary structures were very similar through all the sequences, including the regions of the amino acid substitutions. The main differences were found in the traits 15-21, 84-86 and 91-93. Trait 15-21 was predicted as ss-sheet in wheatwin4 and random-coil in the other proteins. Trait 84-86 was predicted as ss-sheet in wheatwin3 and random-coil in the other proteins. Trait 91-93 was predicted as random coil in wheatwin1 and wheatwin3 and ss-sheet in the other two proteins. Traits 15-21 and 84-86 were exposed, while trait 91-93 was quite hidden in all the proteins. The antifungal activities of the four proteins towards the specific pathogenic fungus Fusarium culmorum were distinct and well correlated to the structural differences. These results suggest that these regions may have a role in the action mechanism, which is still unknown.

Amino Acid Sequence↗