Alberto Spisni | Università degli Studi di Parma (original) (raw)
Papers by Alberto Spisni
The following versions of software and data (see references i O) were used in the production of t... more The following versions of software and data (see references i O) were used in the production of this report:
Biochemical and Biophysical Research Communications, Apr 1, 1988
The transport of glycine was studied in cultured human fibroblasts. The amino acid entered the ce... more The transport of glycine was studied in cultured human fibroblasts. The amino acid entered the cell by Na+-dependent and Na+-independent mechanisms. Na+-independent glycine (0.i mM) transport was less than 10% of total uptake and occurred by a mechanism formally indistinguishable from diffusion. Two distinct routes contributed to Na+-dependent glycine transport. The first route was identified with system A because it was inhibited by MeAIB and underwent adaptive regulation. The second route was identified with system ASC as it was inhibited by L-alanine, but not by MeAIB. Kinetic analysis revealed that the two systems operated glycine transport with the same Km of 1.6 mM, a value unusually high for system ASC.
The following versions of software and data (see references i O) were used in the production of t... more The following versions of software and data (see references i O) were used in the production of this report:
PubMed, Sep 15, 1982
This paper reports on the findings of an antioxidant activity in whole semen from bull and its co... more This paper reports on the findings of an antioxidant activity in whole semen from bull and its components, washed spermatozoa and seminal fluid. The antioxidant activity has been evaluated as the ability of semen or its components to inhibit the spontaneous autooxidation of epinephrine a pH 10, 2, which involves the production of superoxide radicals (0(2)). This preliminary study provides further evidence on the role of free radicals, which are well known to be dangerous to cellular life, and points to the need of a better understanding of the role of antioxidant activities as a cellular protective mechanism.
![Research paper thumbnail of [Lipid-protein interactions in mitochondrial membranes: studies with spin labels]](https://attachments.academia-assets.com/120235110/thumbnails/1.jpg)
](PubMed, Oct 30, 1974
The mitochondrial F 1 F O-ATPase, the key enzyme in cell bioenergetics, apparently works in the s... more The mitochondrial F 1 F O-ATPase, the key enzyme in cell bioenergetics, apparently works in the same way in mollusks and in mammals. We previously pointed out a raft-like arrangement in mussel gill mitochondrial membranes, which apparently distinguishes bivalve mollusks from mammals. To explore the relationship between the microenvironmental features and the enzyme activity, the physico-chemical features of mitochondrial membranes and the F 1 F O-ATPase activity temperature-dependence are here explored in the Manila clam (Ruditapes philippinarum). Similarly to the mussel, clam gill mitochondrial membrane lipids exhibit a high sterol content (42 mg/g protein), mainly due to phytosterols (cholesterol only attains 42% of total sterols), and abundant polyunsaturated fatty acids (PUFA) (70% of total fatty acids), especially of the n-3 family. However, the F 1 F O-ATPase activation energies above and below the break in the Arrhenius plot (22.1 °C) are lower than in mussel and mammalian mitochondria. Laurdan fluorescence spectroscopy analyses carried out at 10°C, 20°C and 30°C on mitochondrial membranes and on lipid vesicles obtained from total lipid extracts of mitochondria, indicate a physical state without coexisting domains. This mitochondrial membrane constitution, allowed by lipid-lipid and lipid protein interactions and involving PUFA-rich phospholipids, phytosterols (much more diversified in clams than in mussels) and proteins, enables the maintenance of a homogeneous physical state in the range 10-30°C. Consistently, this molecular interaction network would somehow extend the temperature range of the F 1 F O-ATPase activity and may contribute to clam resilience to temperature changes.
PubMed, Jun 1, 1984
Sixteen hyperuricemic gouty patients were treated with diflunisal, a novel salicylate, 500 mg BID... more Sixteen hyperuricemic gouty patients were treated with diflunisal, a novel salicylate, 500 mg BID. Serum and urine uric acid along with uric acid clearances were studied before and after a 7-day treatment. A clear hypouricemic action was observed, but 2 different mechanisms of action were seen when overexcretor patients and normoexcretor patients were analyzed separately. In overexcretors an allopurinol-like action was evident, whereas in normoexcretors a uricosuric action occurred. In vitro experiments showed a competitive inhibition of xanthine-oxidase exerted by diflunisal at low concentrations.
Journal of Back and Musculoskeletal Rehabilitation, Jun 26, 2002
Springer eBooks, 1986
It is well recognized that energy transfer in biological processes is closely coupled with ionic ... more It is well recognized that energy transfer in biological processes is closely coupled with ionic gradients across the lipid bilayers of cell membranes. Furthermore, the selectivity of ionic permeation of biomembranes is fundamental to cellular excitability.
The journal of experimental zoology, Sep 1, 1985
An improved method for the isolation of pure plasma and acrosomal membranes from bull spermatozoa... more An improved method for the isolation of pure plasma and acrosomal membranes from bull spermatozoa is presented. Plasma membranes were isolated from the spermatozoa of bulls of different breeds, and some enzymatic activity, such as (Na+-Kf) ATPase, CaffATPase, Mg++ATPase, alkaline and acidic phosphatases were assayed. Such enzymatic activity levels differ noticeably from those published by other authors, whose preparations were probably contaminated by other cellular components. Highly statistically significant differences of these activities have been found among the several breeds.
Journal of Medicinal Chemistry, May 8, 2003
Fibroblast growth factors (FGFs) are regulatory proteins associated with a number of physiologica... more Fibroblast growth factors (FGFs) are regulatory proteins associated with a number of physiological and pathological states. On the basis of data suggesting a functional role for specific regions of human acidic FGF (aFGF), a linear peptide encompassing residues 99-108 (peptide1) and its cyclic analogue (peptide 2) were synthesized and their functional and structural features were investigated. While peptide 1 is inactive on Balb/c 3T3 fibroblasts, peptide 2 is mitogenic with ED 50 of ∼50 µM. Moreover, peptide 1 is not able to inhibit the binding of human aFGF to cellular receptors whereas peptide 2 exhibits significant inhibitory activity. The NMR-derived solution conformers indicated the presence, only in peptide 2, of structural elements that we believe are related to its ability to emulate the biological activity of the native protein. These results suggest that the expression of mitogenic activity in short peptides, besides the presence of specific amino acids, requires the existence of stable structural features. In addition, they indicate that the introduction of chemical restraints in peptides can provide novel possibilities for the development of receptor agonists or antagonists.
Biochemical and Biophysical Research Communications, Sep 1, 1994
Chemischer Informationsdienst, Jun 3, 1986
Synthesis, 1986
Synthese des N-t-butoxycarbonyl-glycine, phenylalanine et -tyrosine et de la t-butoxycarbonyl-1 p... more Synthese des N-t-butoxycarbonyl-glycine, phenylalanine et -tyrosine et de la t-butoxycarbonyl-1 proline
The following versions of software and data (see references i O) were used in the production of t... more The following versions of software and data (see references i O) were used in the production of this report:
Biochemical and Biophysical Research Communications, Apr 1, 1988
The transport of glycine was studied in cultured human fibroblasts. The amino acid entered the ce... more The transport of glycine was studied in cultured human fibroblasts. The amino acid entered the cell by Na+-dependent and Na+-independent mechanisms. Na+-independent glycine (0.i mM) transport was less than 10% of total uptake and occurred by a mechanism formally indistinguishable from diffusion. Two distinct routes contributed to Na+-dependent glycine transport. The first route was identified with system A because it was inhibited by MeAIB and underwent adaptive regulation. The second route was identified with system ASC as it was inhibited by L-alanine, but not by MeAIB. Kinetic analysis revealed that the two systems operated glycine transport with the same Km of 1.6 mM, a value unusually high for system ASC.
The following versions of software and data (see references i O) were used in the production of t... more The following versions of software and data (see references i O) were used in the production of this report:
PubMed, Sep 15, 1982
This paper reports on the findings of an antioxidant activity in whole semen from bull and its co... more This paper reports on the findings of an antioxidant activity in whole semen from bull and its components, washed spermatozoa and seminal fluid. The antioxidant activity has been evaluated as the ability of semen or its components to inhibit the spontaneous autooxidation of epinephrine a pH 10, 2, which involves the production of superoxide radicals (0(2)). This preliminary study provides further evidence on the role of free radicals, which are well known to be dangerous to cellular life, and points to the need of a better understanding of the role of antioxidant activities as a cellular protective mechanism.
PubMed, Oct 30, 1974
The mitochondrial F 1 F O-ATPase, the key enzyme in cell bioenergetics, apparently works in the s... more The mitochondrial F 1 F O-ATPase, the key enzyme in cell bioenergetics, apparently works in the same way in mollusks and in mammals. We previously pointed out a raft-like arrangement in mussel gill mitochondrial membranes, which apparently distinguishes bivalve mollusks from mammals. To explore the relationship between the microenvironmental features and the enzyme activity, the physico-chemical features of mitochondrial membranes and the F 1 F O-ATPase activity temperature-dependence are here explored in the Manila clam (Ruditapes philippinarum). Similarly to the mussel, clam gill mitochondrial membrane lipids exhibit a high sterol content (42 mg/g protein), mainly due to phytosterols (cholesterol only attains 42% of total sterols), and abundant polyunsaturated fatty acids (PUFA) (70% of total fatty acids), especially of the n-3 family. However, the F 1 F O-ATPase activation energies above and below the break in the Arrhenius plot (22.1 °C) are lower than in mussel and mammalian mitochondria. Laurdan fluorescence spectroscopy analyses carried out at 10°C, 20°C and 30°C on mitochondrial membranes and on lipid vesicles obtained from total lipid extracts of mitochondria, indicate a physical state without coexisting domains. This mitochondrial membrane constitution, allowed by lipid-lipid and lipid protein interactions and involving PUFA-rich phospholipids, phytosterols (much more diversified in clams than in mussels) and proteins, enables the maintenance of a homogeneous physical state in the range 10-30°C. Consistently, this molecular interaction network would somehow extend the temperature range of the F 1 F O-ATPase activity and may contribute to clam resilience to temperature changes.
PubMed, Jun 1, 1984
Sixteen hyperuricemic gouty patients were treated with diflunisal, a novel salicylate, 500 mg BID... more Sixteen hyperuricemic gouty patients were treated with diflunisal, a novel salicylate, 500 mg BID. Serum and urine uric acid along with uric acid clearances were studied before and after a 7-day treatment. A clear hypouricemic action was observed, but 2 different mechanisms of action were seen when overexcretor patients and normoexcretor patients were analyzed separately. In overexcretors an allopurinol-like action was evident, whereas in normoexcretors a uricosuric action occurred. In vitro experiments showed a competitive inhibition of xanthine-oxidase exerted by diflunisal at low concentrations.
Journal of Back and Musculoskeletal Rehabilitation, Jun 26, 2002
Springer eBooks, 1986
It is well recognized that energy transfer in biological processes is closely coupled with ionic ... more It is well recognized that energy transfer in biological processes is closely coupled with ionic gradients across the lipid bilayers of cell membranes. Furthermore, the selectivity of ionic permeation of biomembranes is fundamental to cellular excitability.
The journal of experimental zoology, Sep 1, 1985
An improved method for the isolation of pure plasma and acrosomal membranes from bull spermatozoa... more An improved method for the isolation of pure plasma and acrosomal membranes from bull spermatozoa is presented. Plasma membranes were isolated from the spermatozoa of bulls of different breeds, and some enzymatic activity, such as (Na+-Kf) ATPase, CaffATPase, Mg++ATPase, alkaline and acidic phosphatases were assayed. Such enzymatic activity levels differ noticeably from those published by other authors, whose preparations were probably contaminated by other cellular components. Highly statistically significant differences of these activities have been found among the several breeds.
Journal of Medicinal Chemistry, May 8, 2003
Fibroblast growth factors (FGFs) are regulatory proteins associated with a number of physiologica... more Fibroblast growth factors (FGFs) are regulatory proteins associated with a number of physiological and pathological states. On the basis of data suggesting a functional role for specific regions of human acidic FGF (aFGF), a linear peptide encompassing residues 99-108 (peptide1) and its cyclic analogue (peptide 2) were synthesized and their functional and structural features were investigated. While peptide 1 is inactive on Balb/c 3T3 fibroblasts, peptide 2 is mitogenic with ED 50 of ∼50 µM. Moreover, peptide 1 is not able to inhibit the binding of human aFGF to cellular receptors whereas peptide 2 exhibits significant inhibitory activity. The NMR-derived solution conformers indicated the presence, only in peptide 2, of structural elements that we believe are related to its ability to emulate the biological activity of the native protein. These results suggest that the expression of mitogenic activity in short peptides, besides the presence of specific amino acids, requires the existence of stable structural features. In addition, they indicate that the introduction of chemical restraints in peptides can provide novel possibilities for the development of receptor agonists or antagonists.
Biochemical and Biophysical Research Communications, Sep 1, 1994
Chemischer Informationsdienst, Jun 3, 1986
Synthesis, 1986
Synthese des N-t-butoxycarbonyl-glycine, phenylalanine et -tyrosine et de la t-butoxycarbonyl-1 p... more Synthese des N-t-butoxycarbonyl-glycine, phenylalanine et -tyrosine et de la t-butoxycarbonyl-1 proline