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Biomedical subjects

C Caporale

Publications and source records attributed to C Caporale.

16 recordsLinked to original sources
PubMed1991

Assignment of the five disulfide bridges in an alpha-amylase inhibitor from wheat kernel by fast-atom-bombardment mass spectrometry and Edman degradation.

The assignment of the five disulfide bridges in an alpha-amylase monomeric inhibitor from wheat kernel (coded 0.28) was achieved by combining fast-atom-bombardment mass spectrometry (FAB-MS) and automatic sequencing based on Edman degradation. Direct FAB-MS analysis of the native and reduced enzymatic digests of the protein allowed the assignment of three disulfide bridges out of five, including those involving two adjacent cysteine residues. The remaining two disulfide bridges were assigned by sequencing automatically the peptide clusters purified from the tryptic digest of the native protein.

Amino Acid Sequence↗
PubMed1991

Determination of the primary structure of an alpha-amylase inhibitor from wheat kernel by Edman degradation and fast atom bombardment mass spectrometry.

The primary structure of an alpha-amylase inhibitor (coded 0.39) from wheat kernel was determined by fast atom bombardment mass spectrometry and Edman degradation. The sequence is similar to an extent of 97% compared to the other major component of the monomeric isoinhibitor family coded 0.28. The differences consist of the substitution of a single residue and the deletion of two residues in inhibitor 0.39. Neither heterogeneity nor polymorphism were observed in the primary structures of the inhibitors.

Amino Acid Sequence↗
PubMed1990

PROLANG: an expandable software in protein chemistry.

PROLANG is an improved version of the PROSOFT program. Improvements to the old commands were made and new ones were added, PROLANG is an open software that users with BASIC programming experience can easily expand.

Chemical Phenomena↗
PubMed1989

Purification and characterization of a calf thymus protein active on lipid metabolism.

1. This work concerns the purification of a calf thymus protein that increases the binding of human 125I-labeled low density lipoprotein (LDL) on both human skin fibroblasts and a special line of rat liver cells, BRL 3A. 2. It was found that the thymus gland affects cholesterol metabolism via an activation of the LDL receptor pathway. 3. Moreover, the thymus protein active on the LDL receptor pathway has a different amino acid composition and molecular weight from other well-characterized thymic peptides.

Amino Acids↗
PubMed1989

Activity and regulation of calcium-, phospholipid-dependent protein kinase in differentiating chick myogenic cells.

The activity of calcium-, phospholipid-dependent protein kinase (PKc) was measured in (a) total extracts, (b) crude membrane, and (c) cytosolic fractions of chick embryo myogenic cells differentiating in culture. Total PKc activity slowly declines during the course of terminal myogenesis in contrast to the activity of cAMP-dependent protein kinase, which was also measured in the same cells. Myogenic cells at day 1 of culture possess high particulate and low soluble PKc activity. A dramatic decline of particulate PKc activity occurs during myogenic cell differentiation and is accompanied, through day 4, by a striking rise of the soluble activity. The difference in the subcellular distribution of PKc between replicating myoblasts and myotubes is confirmed by phosphorylation studies conducted in intact cells. These studies demonstrate that four polypeptides whose phosphorylation is stimulated by the tumor promoter 12-O-tetradecanoyl phorbol 13-acetate in myotubes, are spontaneously phosphorylated in control myoblasts. Phosphoinositide turnover under basal conditions in [3H]inositol-labeled cells is faster in myoblasts than in myotubes, a finding that may in part explain the different distribution of PKc observed during the course of myogenic differentiation.

Animals↗
PubMed1987

Acetylcholine may regulate its own nicotinic receptor-channel through the C-kinase system.

Acetylcholine (ACh)-activated channel properties were examined on an aneural culture of chick embryo myotubes by using patch-clamp techniques. Changes in conductance, open time and closed time were induced by the selective activator of the calcium- and phospholipid-dependent C-kinase (PKc), 12-O-tetradecanoylphorbol-13-acetate (TPA). The action of TPA was mimicked by exogenous phospholipase C and was blocked by the PKc inhibitor, 1-(5-isoquinolinylsulphonyl)-2-methyl-piperazine. In addition to its gating action, ACh was shown to stimulate phosphoinositide turnover and to translocate PKc from the cytosol to the cell membrane. Both these ACh-induced effects were inhibited by curare and not substantially affected by atropine. Bath-applied ACh outside the patch-pipette in the cell-attached patch-clamp mode, had a strong effect on the ACh-activated channels in the patch membrane, in a way that resembled the action of TPA. These findings raise the possibility that ACh regulates its own nicotinic receptors through the C-kinase system.

Acetylcholine↗
PubMed1986

Altered distribution of protein kinase C in dystrophic muscle cells and its modulation by liposome-delivered phospholipids.

The activity and subcellular distribution of the calcium-phospholipid dependent protein kinase (protein kinase C) were studied in normal and dystrophic muscle cells in vitro. Clonal strains of satellite cells, isolated from normal and dystrophic (C57BL/6J/dydy) mice, differentiate in vitro at a comparable level (over 80% of fusion). Differentiated myotubes were homogenized and separated into a soluble and a particulate fraction. The activity of protein kinase C was assayed in both fractions, and was found to be mainly in the cytosol of normal cells, whereas it was mainly associated to the membrane fraction of dystrophic cells. This altered distribution of the enzyme was likely consequent to alterations in the phospholipid composition of the dystrophic cell membrane, since it was possible to partially revert the situation by modifying the membranes with liposome-delivered phospholipids. Splenic lymphocytes from dystrophic mice showed an altered distribution of protein kinase C similar to that observed in muscle cells. The possible biochemical basis and the functional consequences of this altered distribution of the enzyme in the dystrophic cells are discussed.

Animals↗
PubMed1986

Proliferating and quiescent cells exhibit different subcellular distribution of protein kinase C activity.

The activity of calcium, phospholipid-dependent protein kinase (PKc), which is thought to play an important role in cell proliferation, has been measured in the particulate and soluble fractions of cultured cells, under different proliferative conditions. Our results indicate that proliferating cells display higher PKc activity than quiescent cells. Furthermore, in both normal and transformed cells, PKc is preferentially associated with the particulate fraction when the cells are proliferating, while in mitotically quiescent cells the majority of the enzyme activity is found in the soluble fraction. These data suggest tha PKc activity and subcellular distribution undergo spontaneous changes according to the proliferative state of the cells.

Animals↗
PubMed1986

Calcium-, phospholipid-dependent protein kinase activity of cultured rat Sertoli cells and its modifications by vitamin A.

The activity of the calcium-, phospholipid-dependent protein kinase (PKc) was partially characterized in Sertoli cell cultures prepared from 20-day-old rats. The calcium dependency, the requirements for phosphatidylserine and diolein, as well as the Km for ATP and for the tumor promoter TPA, were determined in total cell extracts. The specific activity of PKc was almost 3-fold higher in the soluble than in the particulate fraction of Sertoli cells. Treatment of cultured Sertoli cells with retinol inhibited, within 1 h of treatment, both the soluble and the particulate fraction-associated PKc activity, with an IC50 of 0.1 microM. Partial inhibition of PKc activity was obtained treating Sertoli cell cultures with FSH, while testosterone was ineffective. However, both FSH and testosterone potentiated the inhibitory effect of retinol. Less differentiated Sertoli cells, obtained from 8-day-old rats, displayed higher PKc activity and a pattern of subcellular distribution of the enzyme opposite to that of Sertoli cells obtained from 20-day-old rats. These data suggest that the actual PKc activity of rat Sertoli cells be negatively regulated by retinol and, spontaneously, during the progression of Sertoli cell differentiation.

Animals↗
PubMed1985

Isolation and characterization of two particle-bound oligoaminopeptidases from human meconium that are different from oligoaminopeptidase of adult small intestine.

Two oligoaminopeptidases (substrate L-leucyl-beta-naphthylamide) have been separated by ion exchange chromatography after Triton solubilization of meconial particles. The quantitatively major form (oligoaminopeptidase II) has been purified to apparent homogeneity. The two meconial oligoaminopeptidases differ from each other in their polyacrylamide gel electrophoretic mobility and isoelectric points. Both meconial enzymes differ from the adult enzyme by having more acidic isoelectric points and different affinities to Helix pomatia lectin-Sepharose columns. Oligoaminopeptidase II has a faster anodal electrophoretic mobility than the adult enzyme but a similar apparent molecular weight and subunit structure. Extensive neuraminidase digestion of meconial oligoaminopeptidase II does not modify the gel electrophoretic mobility of the enzyme. The charge difference between adult and meconial human brush border oligoaminopeptidases is therefore probably due, at least in part, to differences in the carbohydrate composition of these glycoproteins, and differences in the number of terminal or exposed sialic acid residues do not explain the observed charge differences.

Adult↗
PubMed1976

Stable, inducible thermoacidophilic alpha-amylase from Bacillus acidocaldarius.

Bacillus acidocaldarius Agnano 101 produces an inducible thermoacidophilic alpha-amylase. The enzyme production occurs during the stationary phase of growth in the presence of compounds with alpha-1,4-glucosidic linkages. The enzymatic activity is both present in the culture medium and associated with the cells; the enzymes purified from both sources show identical molecular and catalytic properties. The purified amylase has a single polypeptide chain of molecular weight 68,000 and behaves like an alpha-amylase with affinity constants for starch and related substances of 0.8 to 0.9 mg/ml. The pH and temperature optima for activity are 3.5 and 75degreesC, respectively. The amylase is stable at acidic pH (below 4.5). Its thermal stability is strictly dependent upon protein concentration; the half-life at 60degreesC of the amylase in a 70-mug/ml solution is about 5 days.

Amylases↗
PubMedDate not supplied

[Pre- and postoperative ECG-VCG study of the correction of atrioventricular septal defects].

In order to determine the possible implication of the right bundle branch block (RBBB) in the superior axis deviation of patients (pt) affected with AV septal (Canal) defect, we studied the preoperative and postsurgical ECG of 50 patients who underwent radical correction of the malformation complex. 36 pt had the complete form and 14 a partial form. In 14 of them it was also possible to perform a VCG before and after surgery. The amplitude of S1, R' in a VR and V1 modified significantly (p less than 0.0001), the AQRS showed a clockwise displacement of 19 degrees (p less than 0.002). The terminal forces in the VCG frontal plane changed significantly 62 degrees (p less than 0.0001). Nevertheless the D.I. in a VL and V6 made no difference. Postoperative ECG patterns of pt with partial or complete forms did not differ substantially. Results allowed us to conclude that the major determinant of the AV septal defect ECG pattern is the posterior (inlet) deficiency of the interventricular septum. Surgical correction of the right ventricle overload leads to a clockwise AQRS displacement in the frontal plane. The conduction asynchronism through the left branch showed no modifications.

Adolescent↗