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P Man

Publications and source records attributed to P Man.

8 recordsLinked to original sources
PubMed2004

N-glycosylated catalytic unit meets O-glycosylated propeptide: complex protein architecture in a fungal hexosaminidase.

beta-N-Acetylhexosaminidase from a filamentous fungus Aspergillus oryzae is a secreted enzyme known to be an important component of the binary chitinolytic system. Cloning of the hexA gene and sequencing of the enzyme revealed its unique preproprotein structure. While the enzyme's zincin-like and catalytic domain had significant similarities with members of the glycohydrolase 20 family, the propeptide was unique for the fungal enzyme. Detailed pulse-chase and inhibition studies revealed that propeptide was processed during the biosynthesis of the enzyme. Moreover, the presence of propeptide was necessary for enzyme activation, dimerization and secretion. The catalytic unit was N-glycosylated, and the propeptide was O-glycosylated, both in their C-terminal parts. Deglycosylation experiments revealed that the N-glycosylation increased the stability and solubility of the enzyme. In contrast, O-glycosylated propeptide was necessary to attain the full enzymic activity.

Aspergillus oryzae↗
PubMed2004

Mass spectrometry is a powerful tool for identification of proteins associated with lipid rafts of Jurkat T-cell line.

Many proteins involved in signal-transduction pathways are concentrated in membrane microdomains enriched in lipids with distinct physical properties. Since these microdomains are insoluble in non-ionic detergents in cold, proteins associated with them could be efficiently purified by techniques such as sucrose-density gradient centrifugation. The complexity of the resulting protein mixture requires powerful MS technique for its analysis. We have found that successful identification of biologically relevant proteins is critically dependent on the enrichment of the starting material (plasma membranes), and on the extraction procedure. Applying these conditions in combination with microHPLC-ESI (electrospray ionization)-MS/MS, we have identified proteins involved in signalling, cytoskeletal association and cellular adhesion in Jurkat cells that are not stimulated by any antibody incubation.

Cell Adhesion↗
PubMed2003

Purification and characterization of a saccharide-binding protein from penetration glands of Diplostomum pseudospathaceum--a bifunctional molecule with cysteine protease activity.

A beta-1,3-glucan-binding lectin from the penetration glands of Diplostomum pseudospathaceum cercariae was isolated by affinity chromatography using yeast glucan and curdlan as affinity matrices. Further purification to homogeneity was performed by cation-exchange chromatography. The protein migrated as a double band around 24 kDa in gels after SDS-PAGE. The protein is of strongly basic nature--its pI shown by native IEF was around 10. The mass of the protein determined by MALDI-TOF mass spectrometry was 23.9 kDa. N-terminal sequence as well as some internal sequences showed significant alignments with several cysteine protease sequences found in databases. The protein bound a biotinylated synthetic analogue of the irreversible inhibitor of cysteine proteases, E-64 and, moreover, its proteolytic activity was demonstrated in substrate gels. The enzymatic activity could be inhibited by the cysteine protease inhibitor E-64; therefore, the investigated protein was considered to be a bifunctional molecule possessing both lectin and enzyme activities. Glycanohydrolytic activity was not proved. The detected characters of this molecule lead to a hypothesis on its role in penetration of Diplostomum cercariae into fish hosts--that of binding to the carbohydrates of fish mucus and concurrent cleaving of protein components of the mucus and skin.

Amino Acid Sequence↗
PubMed2001

Characterization of the rplB gene from Streptomyces collinus and its protein product by mass spectrometry.

Ribosomal protein L2 is the largest protein components of 50S subunits. The protein is implicated in peptidyl transferase activity and binds to functionally important domains of 23S rRNA. The rplB gene, which codes for ribosomal protein L2 was cloned from Streptomyces collinus. The gene rplB was isolated from BamHI fragment (3.0 kb) of chromosomal DNA possessing two partial and four complete ORF's in the order from 5' to 3': rplC, rplD, rplW, rplB, rpsS, and rplV. The gene organization corresponds to the S10 operon. Gene rplB (834 bp) encodes a polypeptide chain of 278 amino acids. The molecular mass calculated from genomic structure is 30.5 kDa and pI 11.87. Protein L2 is rich in positively charged amino acids (Arg 36, Lys 20, and His 11). N-terminal domain possesses topology similar to the oligonucleotide/oligosaccharide binding OB folds. The availability of genome sequence makes it possible to identify L2 protein by mass spectrometry, moreover it facilitates the characterization of its potential posttranslational modifications. To confirm the protein sequence derived from the rplB gene the tryptic peptides of L2 were analyzed by mass spectrometric techniques. The obtained data matched exactly with the results of DNA sequencing.

Bacterial Proteins↗
PubMed2000

Use of focus groups to assess the educational needs of the primary care physician for the management of asthma.

OBJECTIVES: To determine the educational needs of primary care physicians, in the management of patients with asthma. DESIGN: Focus group discussions with physicians, pharmacists, respiratory therapists and patients. SETTING: Metropolitan Edmonton, Alberta, Canada. PARTICIPANTS: Out of an original mail request to 100 potential recruits, 52 people attended the focus group sessions. These included physicians, pharmacists, respiratory therapists, adult patients and paediatric patients accompanied by their parents. MAIN OUTCOME MEASURE: Consensus of the specific group being interviewed using facilitator-mediated responses, to identify problems in the care of asthma patients and appropriate educational methods to improve the situation. RESULTS: Both diagnostic and treatment concerns were identified by the primary care physicians and others in the study. Confusion with infection was the most common diagnostic problem. Major treatment problems involved confusion about aspects of management strategy and a lack of communication between physicians, patients and other members of the health care team. Poor patient compliance and patients changing doctors frequently were also of major concern. There were inconsistencies in the treatment of asthma between physicians. While most physicians felt that they were up-to-date in management, Asthma Control Guidelines were seldom followed. CONCLUSIONS: There is an urgent need for continuing medical education, not only in management but also in communication with patients and with other members of the health care team. The data permit the development of an ongoing educational programme which is practical and designed to deal with the issues identified in this survey.

Alberta↗
PubMed2000

Underuse of inhaled corticosteroids in adults with asthma.

Despite strong evidence that inhaled corticosteroids are beneficial in treating asthma, a number of small studies suggest a use rate of only 34-56%. The primary objective of this study was to determine patterns of prescribing inhaled corticosteroids for high-risk patients with asthma. Secondary objectives were to assess patterns of practice with respect to other agents prescribed before and at hospital discharge, and to determine if an emergency room asthma care map at one of the study hospitals was being followed. We retrospectively reviewed charts of 1022 patients with an acute attack of asthma treated in the emergency rooms of the Royal Alexandra Hospital and University of Alberta Hospital from January 1, 1996, to March 31, 1997. A forward stepwise logistic regression analysis was performed with the dependent variable defined as whether or not the patient was using an inhaled or oral corticosteroid during the index visit, and the independent variable being all major demographic variables. Inhaled corticosteroids were prescribed for 460 patients (52.0%) at the index visit. Overall, antiinflammatory drugs were prescribed for 548 patients (62.1%). An asthma care map was followed for 107 (16.8%) patients treated at the Royal Alexandra Hospital at the index visit. Logistic regression analysis showed that women and patients with more than one emergency room visit most likely were to be using inhaled or inhaled plus oral corticosteroids at the index visit. Documentation of drug therapy at discharge was poor for 42% of patients; therefore, analysis of practice patterns in this group was not attempted. This study shows that inhaled corticosteroids were prescribed for only about one-half of patients with an acute asthma attack. Given this low use by high-risk patients, the need for programs designed to improve asthma therapy is evident.

Administration, Inhalation↗
PubMed1985

Atrial reflexes during high frequency oscillatory ventilation.

High frequency oscillatory ventilation (HFOV) is a new method of artificial ventilation which has been advocated for use in critically ill individuals. It alters the discharge in pulmonary stretch receptors (SAR) from a phasic to a continuous pattern. Since some cardiovascular neurones in the medulla are influenced by the discharge from SAR, experiments were undertaken to determine whether the reflexes from the left atrial (volume) receptors (LAR) were influenced by HFOV. The reflex increases in heart rate and urine flow which result from activation of the (LAR) were examined during both intermittent positive pressure ventilation (IPPV) and HFOV. In five dogs, the increase in heart rate was 23.9 +/- 4.3 and 24.5 +/- 5.4 beats/min during IPPV and HFOV, respectively. In six dogs the response of an increase in urine flow was examined and this response also was not altered by HFOV. It is concluded that the integrity of these reflexes was unaffected by HFOV in the anesthetized dog model.

Animals↗