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Biomedical subjects

P Pucci

Publications and source records attributed to P Pucci.

At least 127 records · Page 7Linked to original sources
PubMed1988

Substance P as a transglutaminase substrate: identification of the reaction products by fast atom bombardment mass spectrometry.

Substance P was found to be an effective acyl donor substrate of transglutaminase in vitro, the reaction products having been examined by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fast atom bombardment mass spectrometry. Electrophoretic experiments showed that Substance P incorporated 14C-labeled polyamines when incubated with purified guinea pig liver transglutaminase and Ca2+. Extensive use of fast atom bombardment mass spectrometry allowed to establish that: i) a 1:1 adduct Substance P-spermine is formed; ii) only a single glutamine residue out of two, i.e. Gln-5, acts as acyl donor, iii) the single lysine residue of the neuropeptide is unable to act as acyl acceptor. A direct analytical methodology to detect transglutaminase reaction products is described.

Animals↗
PubMed1988

Beta-endorphin modification by transglutaminase in vitro: identification by FAB/MS of glutamine-11 and lysine-29 as acyl donor and acceptor sites.

FAB-Mapping strategy was successfully exploited to characterize the reaction products of the transglutaminase-mediated modifications of human beta-endorphin in vitro. The GLN-11 residue of the neuropeptide was shown to be an effective acyl donor site for the enzyme, being able to bind spermine in the presence of Ca2+. Moreover, only one out of five lysyl residues (LYS-29) was demonstrated to act as acyl acceptor crosslinking with GLN-11.

Acylation↗
PubMed1988

Identification by fast atom bombardment mass spectrometry of Hb Indianapolis [beta 112(G14)Cys----Arg] in a family from Naples, Italy.

We have characterized a beta 112 Arg hemoglobin in an individual from Naples, Italy, with minimal clinical problems. Blood tests revealed only slight reticulocytosis and hemoglobin instability. Furthermore, high value of alkali resistance tests for Hb F were observed. Isoelectricfocusing of globins showed the occurrence of a band migrating between the normal alpha and beta globin chains. The fairly stable variant chain was purified by fast protein liquid chromatography. A mass map of the tryptic digest was obtained by fast atom bombardment mass spectrometry clearly showing that we were dealing with a beta chain variant. However, the peptide 105-120 was missing and two new ones were present, i.e.: 105-112 and 113-120; we assumed these peptides to be generated because of the substitution of 112 Cys with an arginine residue. Further confirmation stemmed from the fast atom bombardment mass spectra of the tryptic digest submitted to a single Edman degradation step and to carboxypeptidase B further hydrolysis. The beta-globin chain variant was thus mass mapped to an extent of about 98%. Such a variant, named Hb Indianapolis, was first reported by Adams et al, as an extremely unstable variant producing the phenotype of a severe beta-thalassemia. Contrary to the findings of the above authors the occurrence of the same variant in a clinically normal individual from a Spanish family has recently been reported. Because the clinical manifestations in the latter case are similar to those observed by us, the conclusion can be drawn that beta 112 Arg hemoglobin is not a biologically unstable variant but should be regarded as belonging to the class of unstable hemoglobins giving rise to only marginal clinical problems.

Adult↗
PubMed1987

Digestion by pancreatic juice of a beta-casomorphin-containing fragment of buffalo beta-casein.

Degradation by pig pancreatic juice of a beta-casomorphin-containing fragment (tryptic peptide corresponding to residues 49-68 of buffalo beta-casein) was investigated. The FAB/MS (fast atom bombardment mass spectrometry) technique was used to identify the fragments produced by the concerted action of pancreatic proteases. Pancreatic juice, under our experimental conditions, is not able to release beta-casomorphins or morphiceptin from the tryptic peptide sequence. Furthermore, the present report shows that the rapid hydrolysis of a peptide bond by a single protease can prevent the cleavage of peptide bonds by a different protease. Therefore the formation of some peptides in the gastrointestinal tract can depend on the protease ratio.

Animals↗
PubMed1986

Assignment of phosphorylation sites in buffalo beta-casein by fast atom bombardment mass spectrometry.

Fast atom bombardment mass spectrometry has been applied to the localization of phosphorylation sites in buffalo beta-casein. Two complementary strategies of identification are described. Phosphorylated residues in the tryptic peptide Tp 1 have been assigned by measuring the masses of peptide fragments obtained by enzymatic degradations. The phosphoserine residue in peptide Tp 2 has been identified by determining the intact molecular weight and confirmed by partial sequence information. This rapid and sensitive procedure appears of a great interest in structural studies of a wide range of post-translational modifications in proteins.

Amino Acid Sequence↗
PubMed1985

Protein fingerprint by fast atom bombardment mass spectrometry: characterization of normal and variant human haemoglobins.

A procedure using fast atom bombardment mass spectrometry was developed for mapping the proteolytic digest of proteins. The procedure was successfully applied to the tryptic peptides of the human beta-globin chain. Almost all the expected peptides were identified by direct analysis of the peptide mixture on the mass spectrometer. Peptide recognition along the beta-globin chain sequence was easily made on the basis of their molecular weight. The general applicability of this mapping procedure in the analysis of haemoglobinopathies was demonstrated by its use for the structural characterization of a variant beta-globin chain.

Amino Acid Sequence↗
PubMed1985

A new method for rapid assignment of S-S bridges in proteins.

A new method for complementing existing protein chemical techniques for the assignment of S-S bridge positions in amino-acid sequences is described. The principle of the method is the direct examination of the masses of protein fragments, obtained by chemical or enzymatic degradation. Proteins are digested under conditions known to minimise disulphide reduction and reshuffling, and the unfractionated digest is examined directly by high field magnet (or other high mass) fast atom bombardment or Californium mass spectrometry. Disulphide linked peptides are identified from their unique masses, and by comparison with the spectrum of digested and reduced samples in which the signal corresponding to the S-S linked peptide(s) is replaced by two signals corresponding to the respective thiol peptide components, if INTER-bridged, or shifted by two mass units (dithiol) if INTRA-bridged. This rapid procedure has considerable potential in assisting with studies on the primary structure of proteins, in crystallographic studies and the monitoring of denaturation/renaturation of recombinant proteins.

Carboxypeptidases↗
PubMed1984

Modified calmodulin calcium binding domain III. Solid phase synthesis, purification and 1H n.m.r. characterization.

The dodecapeptide Ac-Asp-Lys-Asp-Gly-Asn-Gly-Tyr-Ile-Ser-Ala-Ala-Gaba-OH is a modified calmodulin calcium binding domain III. The synthesis of the peptide by the solid phase method with a total protection scheme using PAM-resin is reported. The purified compound has been characterized by 1H n.m.r. spectroscopy, both in the presence and in the absence of calcium ions, at various pHs. No strong specific interaction seems to occur between the peptide and Ca++ ions in water solutions.

Binding Sites↗
PubMed1983

Silent myocardial ischemia during ambulatory electrocardiographic monitoring in patients with effort angina.

The frequency and characteristics of asymptomatic ischemic attacks were investigated in 39 patients with effort angina. During 24 hour Holter monitoring, 32 of the 39 patients displayed one or more episodes of ischemic ST depression. Eight patients had attacks (n = 25) always accompanied by pain; 9 patients had only asymptomatic ischemic episodes (n = 40) and 15 patients had both symptomatic (n = 29) and asymptomatic attacks (n = 76). In the 15 patients exhibiting both symptomatic and asymptomatic attacks, mean duration of symptomatic episodes was longer (probability [p] less than 0.001) and mean maximal ST depression was greater (p less than 0.001). When patients exhibiting only symptomatic episodes were compared with those exhibiting only asymptomatic attacks, differences were not significant. All symptomatic and asymptomatic attacks during Holter monitoring were correlated with the results of stress testing: patients experiencing a delayed response to pain after the onset of St ischemic depression during stress testing had a higher ratio of asymptomatic to symptomatic attacks during Holter monitoring compared with those patients reporting pain before or at the moment of the appearance of ischemic electrocardiographic features during stress testing. It is concluded that: 1) asymptomatic episodes of ischemia are more frequent than symptomatic episodes in patients with effort angina; 2) in the same patient, the severity of ischemia is generally a fundamental factor in determining the presence or absence of pain during an ischemic attack; and 3) differences among patients with respect to predominance of symptomatic or asymptomatic attacks probably depend on individual factors.

Angina Pectoris↗
PubMed1983

Studies on gliadin related peptides. I. Synthesis, purification and 1H n.m.r. characterization of the pentapeptide H-Tyr-(Gln)3-Pro-OH.

The pentapeptide H-Tyr-(Gln)3-Pro-OH has been recently postulated to be the basic repetitive unit of a sequential polypeptide contained in wheat bread alpha-gliadins, which are believed to be toxic factors in coeliac disease, gluten-dependent enteropathy. Solid-phase synthesis, purification and 1H n.m.r. characterization in water solution of this peptide are described.

Chromatography, High Pressure Liquid↗
PubMed1983

[Evaluation of a new percutaneous nitroglycerin preparation in effort angina].

In 10 subjects with constant threshold effort angina ascertained by two bicycle exercise tests, the efficacy of a new transdermal preparation of nitroglycerin (104 mg) applied once daily was evaluated and compared to that of oral long-acting isosorbide dinitrate (20 mg every 8 hours). The two drugs were administered according to a complete crossover plan. The effectiveness of each drug was evaluated by testing the patients before treatment, on the third and on the twenty-first hour of treatment. In each case the exercise was continued until electrocardiographic signs of ischemia appeared. The total work during treatment with transdermal nitroglycerin was significantly higher (average increase greater than 44%) than without the drug (1311 +/- 545 Kgm before treatment, 2145 +/- 968 Kgm at the third hour, 1899 +/- 657 Kgm at the twenty-first hour of treatment). Similar results were obtained during treatment with isosorbide dinitrate (1332 +/- 581 Kgm before treatment, 1837 +/- 526 at the third hour, 1869 +/- 570 at the twenty-first hour of treatment; average work increase greater than 37%). In conclusion, with this new transdermal preparation of nitroglycerin an increased work-load can be achieved before ischemia appears. Its beneficial action remains constant for 21 hours.

Adult↗
PubMed1983

[Thyroid function in patients chronically treated with amiodarone].

The effects of Amiodarone (1000-1400 mg/week, for a period ranging from 3 to 24 months) on thyroid gland function were studied in 45 patients with heart disease, using a new method of free thyroid hormone assay. Forty-four untreated patients and 11 normal subjects were used as controls. In treated patients the prevalence of dysthyroidism was 22,2% (15,6% hypothyroidism and 6,6% hyperthyroidism); the onset of dysthyroidism ranged from 20 days to 2 years after the beginning of treatment. In control patients the prevalence of dysthyroidism was 4,4% (2,2% hypothyroidism and 2,2% hyperthyroidism). In patients with hypothyroidism (TSH greater than 7 microunits/ml) T4 levels were generally low, while T3, fT4 and fT3 levels were normal. In treated patients with hyperthyroidism (fT3 greater than 5,3 pg/ml and fT4 greater than 16 pg/ml) T4 values were high, while T3 concentrations were in the normal range. In Amiodarone-treated euthyroid patients, mean T4, fT4 and rT3 values were significantly (p less than 0,01) higher than those of control subjects; TSH levels were normal in all the groups studied. These data suggest that Amiodarone can exert both a direct effect on the thyroid gland and the peripheral metabolism of thyroid hormones. The action on the thyroid gland is suggested by the high prevalence of dysthyroidism in Amiodarone-treated patients and by the high levels of T4 and fT4 observed in patients who did not show dysthyroidism. The action on the peripheral hormonal metabolism seems to be proved by the high levels of rT3 and by the prolongation of QTc interval.

Aged↗
PubMed1981

Reactivity of sulphydryl groups of cytosolic and mitochondrial bovine aspartate aminotransferases.

Reactivity of sulphydryl groups of cytosolic and mitochondrial aspartate aminotransferases from ox heart has been studied. A total of 5 and 7 cysteine residues per monomer are present in cAATo and mAATo, respectively. In native conditions only a single sulphydryl group can be titrated by Nbs2 while the catalytic activity remains unchanged, however in the mitochondrial isozyme the reactivity depends on the functional state of the enzyme. Reactivity toward NEM reveals the existence of a syncatalytic sulphydryl group in the cytosolic isozyme. Titration of cAATo with pMB at pH 8 and pH 5 confirms the existence of two exposed sulphydryl groups with a different reactivity. The results compared with those reported on the corresponding isozymes from pig and chicken heart show that syncatalytic sulphydryl groups are of general occurrence in these enzymes.

Animals↗