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F Panara

Publications and source records attributed to F Panara.

At least 37 records · Page 2Linked to original sources
PubMed1990

Purification and subcellular localization of Zn-dependent acid p-nitrophenylphosphatase in frog liver and comparison with other vertebrates.

Zn2(+)-dependent acid p-nitrophenylphosphatase (Zn-AcPase) from liver of Rana esculenta was purified to homogeneity. The purified enzyme moves as a single electrophoretic band at pH 8.3 in 7.5% acrylamide and was coincident with the enzyme activity. The enzyme has a molecular weight of 102,000 +/- 5,000D and is a dimer with two apparently similar polypeptide chains of 48,000 +/- 3,000D as determined by sodium dodecylsulfate gel electrophoresis. Zn-AcPase from frog liver requires Zn2+ ions for catalytic activity; other bivalent cations have little or no effect. The enzyme with a pI of 7.07 does not appear to be a glycoprotein and was associated with the soluble fraction after liver cell fractionation. The biochemical and molecular properties of frog liver Zn-AcPase were compared with that of the enzyme partially purified from carp (Cyprinus carpio), pike (Esox lucius), and rat (Rattus norvegicus).

4-Nitrophenylphosphatase↗
PubMed1989

Functional aspects of calcium transport in sarcoplasmic reticulum vesicles derived from frog skeletal muscle treated with saponin.

To study the physiological aspects of the excitation-contraction cycle, saponin (10-100 micrograms ml-1) was used as a skinning agent on muscle and sarcotubular vesicles derived from fast muscles (sartorius and tibialis anterior) of Rana esculenta. The vesicles showed similar Ca2+-ATPase activity and similar protein profiles carried out by SDS-PAGE. Calcium transport in untreated vesicles and those treated with different concentrations of saponin seemed to have the same quantitative and qualitative parameters if the saponin was used in a range between 10 and 50 micrograms ml-1. Our results confirm that saponin may be considered to be a valid skinning agent for the external membranes of fast skeletal muscles.

Animals↗
PubMed1989

Acid phosphatases from liver of Rana esculenta. Subcellular localization and partial characterization of multiple forms.

1. Four acid phosphatases (AcPase I, II, III and IV) were found in the liver of the frog Rana esculenta. 2. AcPases I, II, III, and IV were associated with the microsomal, mitochondrial-lysosomal, nuclear and soluble fractions respectively and showed apparent molecular weights of about 240,000, 110,000, 38,000 and 17,000. 3. All the enzymes show acid pH optima, and similar Km values for p-nitrophenylphosphate. 4. AcPases I, II, and III hydrolyze most of the common phosphate esters whereas AcPase IV hydrolyzes effectively only p-nitrophenylphosphate, phenylphosphate and flavine mononucleotide. 5. AcPases I and II are inhibited by NaF and tartrate. AcPases III and IV are tartrate resistant. 6. Temperature inhibits AcPases I, II, IV, whereas it activates AcPase III.

Acid Phosphatase↗
PubMed1988

Zn2+-dependent acid p-nitrophenylphosphatase from chicken liver. Purification, characterization and subcellular localization.

1. Zn2+-dependent acid p-nitrophenylphosphatase from chicken liver was purified to homogeneity. 2. The purified enzyme moves as a single electrophoretic band at pH 8.3 in 7.5% acrylamide and was coincident with the enzyme activity. 3. Gel filtration on Sephadex G-200 gave an apparent molecular weight of 110,000 with two apparent identical subunits of 54,000-56,000 as determined by sodium dodecyl sulphate gel electrophoresis. 4. The maximum of enzyme activity was obtained in the presence of 3-5 mM ZnCl2 at pH 6-6.2, however, higher concentrations of metal are inhibitory. The enzyme hydrolyses p-nitrophenylphosphate, o-carboxyphenylphosphate and phenylphosphate, was insensitive to NaF and was inhibited by phosphate and ATP. The Km for p-nitrophenylphosphate was 0.28 x 10(-3)M at pH 6 in 50 mM sodium acetate/100 mM NaCl. 5. Phosphate is a competitive inhibitor (Ki = 0.5 x 10(-3)M) whereas ATP seems to be a non-competitive inhibitor (Ki = 0.35 x 10(-3)M). The isoelectric point determined by isoelectric focusing on polyacrylamide gel is 7.5. 6. Cell fractionation studies indicate that the Zn2+-dependent acid p-nitrophenylphosphatase of chicken liver is a soluble enzyme form.

4-Nitrophenylphosphatase↗
PubMed1987

The minor haemoglobins of primitive and definitive erythrocytes of the chicken embryo. Evidence for haemoglobin L.

A new minor haemoglobin, L, was isolated from the haemolysates of chicken embryos more than 7 days old. Electrophoresis in denaturing conditions and tryptic peptide maps of the globins show that the beta-like globin of HbL is identical to that of the minor haemoglobin H(beta H) while the alpha-like globin is very similar to that of the adult haemoglobin D (alpha D). HbL completes the description of the map of the minor chicken haemoglobins during embryonic development. In early embryos two minor haemoglobins, M and E, are produced which have the same beta-like globin (epsilon) and differ in their alpha-like globins (alpha D and alpha A, respectively). The same two alpha-like globins will make up the minor haemoglobins of the late embryo, L and H, which differ from HbM and HbE on account of their beta-like globin (beta H). The native tetramers L and M are hard to distinguish from each other. However the constituent epsilon globin can be easily separated from beta H by electrophoresis on polyacrylamide gel in formic acid. With this method we found that the switch of the minor haemoglobins in the blood of chicken embryos starts at the 7th incubation day. The two red cell populations, primitive and definitive, present in the blood of 7-day-old embryos were separated on an albumin gradient and their minor haemoglobins analysed. The haemoglobin couple M/E was found in the primitive erythroid cells whereas the L/H couple was found in the definitive ones. The disappearance of the early haemoglobin couple and its substitution by the late one during embryonic development correlates with the replacement of erythroid lines in the blood.

Animals↗
PubMed1986

The presence of a Zn2+-dependent acid p-nitrophenyl phosphatase in bovine liver. Isolation and some properties.

The presence of a Zn2+-dependent acid p-nitrophenyl phosphatase (EC 3.1.3.2) in bovine liver was described. The enzyme was purified to apparent homogeneity and migrates as a single band during electrophoresis on polyacrylamide gel. The enzyme requires Zn2+ ions for catalytic activity, other bivalent cations have little or no effect. The enzyme, of Mr 118,000, optimum pH 6-6.2 and pI 7.4-7.5, was inhibited by EDTA, tartrate, adenine and ATP, but not by fluoride. The common phosphate esters are poor substrates for the enzyme, which hydrolyses preferentially p-nitrophenyl phosphate and o-carboxyphenyl phosphate. The Zn2+-dependent acid p-nitrophenyl phosphatase of bovine liver was different from the high-Mr acid phosphatases previously detected in mammalian tissues.

4-Nitrophenylphosphatase↗
PubMed1986

Subcellular localization of high- and low-molecular weight acid phosphatases from chicken liver.

The subcellular localization of high and low molecular weight acid phosphatases in chicken liver was studied. The high molecular weight acid phosphatase is mainly associated with the particulate fraction, particularly with the mitochondrial-lysosomal fraction, whereas the low molecular weight form seems to be a soluble cytoplasmic enzyme. Biochemical properties including optimal pH, molecular weight determination and the effect of some modifier substances indicate that mitochondria-lysosomes and microsomes contain the same high molecular weight acid phosphatase form.

Acid Phosphatase↗
PubMed1986

Hemoglobin heterogeneity in the pike, Esox lucius, and isolation of a homogeneous component.

The hemolysate of the pike, Esox lucius, contains multiple molecular forms of hemoglobin molecules. Analytical gel electrofocusing, disc-gel electrophoresis and gel filtration chromatography indicate that the hemoglobin heterogeneity may be due to different charge isomers with mol. wt values similar to that of the human. Ion exchange chromatography on CM-cellulose permits to separate a hemoglobin component in a pure form. Globin chains analysis of this fraction and their isolation was also reported.

Animals↗
PubMed1980

Localization of acid phosphatases in the cell fractions of chick liver.

3 molecular forms (P1, P2 and P3) of acid phosphatase (E.C. 3.1.3.2) have been detected in chicken liver homogenate. The different intracellular localization of these molecules has been demonstrated by cellular fractionation and electrophoretic analysis. P1 and P2 phosphatases are both present in the particulate fraction. P3 is present in a pure form in the soluble fraction. The difference between the enzyme molecules present in the particulate fraction and that in the soluble one is confirmed by the different activation-inhibition effect of various ions and substances on the enzymatic activity of subcellular fractions.

Acid Phosphatase↗
PubMed1980

The haemoglobins of developing duck embryos.

Three haemoglobins were isolated by ion-exchange chromatography from the haemolysates of embryonic duck erythrocytes up to 8 days of development. The component globins were characterized both by electrophoresis in dissociating conditions and by finger-printing analysis. The major haemoglobin fraction E1 appears to be an embryonic tetramer since its constituent globins are different from all the others synthesized during embryonic and adult life. The two minor fractions E2 and E3 show alpha-type subunits that are very similar to those of the two adult haemoglobins A1 and A2 respectively. They are present all through embryonic life, as demonstrated by chromatographic analysis. For these reasons they have been considered foetal. The two haemoglobins typical of the adult animal are found in the red cells of the embryo from 8 days of incubation. Their relative amounts change continuously during embryonic development and reach the adult value after hatching.

Animals↗
PubMed1978

Acid and alkaline phosphatase heterogeneity in liver, heart and intestine of the adult chick.

The molecular heterogeneity of acid and alkaline phosphatase from chick liver, intestine and heart is demonstrated by polyacrilamide disc gel electrophoresis. Liver and heart show the same number of molecular forms of acid and alkaline phosphatases. In contrast, the intestine homogenate shows electrophoretic bands different in number and in gel position from those of the liver and of the heart.

Acid Phosphatase↗