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At least 811 records · Page 45Linked to original sources

PubMed1994

Effects of cholic acid and 'Protectaid' formulations on human sperm motility and ultrastructure.

Cholic acid (sodium cholate) and the other active ingredients of F-5 gel preparations in use for the impregnation of a new vaginal sponge (Protectaid) with contraceptive and anti-sexually transmitted disease properties, were assessed for their effects on human sperm motility and ultrastructure. Cholic acid (CA) produced an inhibition of motility which was both dose- and time-dependent. A complete suppression of motility was obtained at 30 s by a CA concentration of 1.25%. Nonoxynol-9 (NX9) compared with benzalkonium chloride (BZC) showed no significant difference at the concentration required (0.025%) to give a total inhibition of sperm motility after exposure for 30 s. The addition of F-5A gel containing 0.5% of each one of the spermicide ingredients (CA, NX9 and BZC) produced the total suppression of sperm motility within 30 s at a dilution of 1/50. Another preparation, F-5B gel, containing the spermicide ingredients at different concentrations (1.25% CA, 0.125% NX9 and 0.05% BZC) produced this same effect with a 1/10 dilution. Exposure of semen to a CA concentration of 1.25% or to 1/10 dilutions of F-5A gel for 30 s led to profound changes of sperm ultrastructure studied by scanning (SEM) and transmission (TEM) electron microscopy. SEM and TEM findings indicate that CA acts as a spermicide through its 'natural detergent' properties, damaging the outer plasma membrane of sperm cells. Protectaid formulations affect sperm motility and viability in a similar way.

Acrosome↗

PubMed1986

Partial purification and characterization of membrane-bound and cytosolic phosphatidylinositol-specific phospholipases C from murine thymocytes.

Membrane-bound and cytosolic phosphatidylinositol (PI)-specific phospholipases C in murine thymocytes have been partially purified and characterized. The membrane-bound enzyme was extracted from microsomes with sodium cholate and purified by sequential column chromatographies on Sephadex G-100, heparin-Sepharose CL-6B, and Sephadex G-100. The cytosolic enzyme was purified from the cytosol by sequential column chromatographies on Sephadex G-100 and FPLC-Mono S. Specific activities of the membrane-bound enzyme and the cytosolic enzyme increased more than 1,800- and 1,400-fold, respectively, compared with those of microsomes and the cytosol. The molecular weights of the both enzymes were estimated to be about 70,000 by gel filtration. These purified enzymes also hydrolyzed phosphatidylinositol 4,5-bisphosphate (PIP2). At neutral pH and low Ca2+ concentrations, the membrane-bound enzyme hydrolyzed PIP2 in preference to PI and showed higher activity than the cytosolic enzyme. These activities were also affected differently by various lipids. For PIP2 hydrolysis, all lipids investigated except lysophosphatidylcholine enhanced the activity of the membrane-bound enzyme, while phosphatidylcholine (PC) and phosphatidylserine (PS) did not significantly affect the activity of the cytosolic enzyme. PC, PE, and PS inhibited the activities of the membrane-bound and cytosolic enzymes for PI hydrolysis. The physiological implications of these results are discussed.

Animals↗

PubMed1987

Human placental sialidase: partial purification and characterization.

A sialidase [EC 3.2.1.18] has been partially purified from human placenta by means of procedures comprising Con A-Sepharose adsorption, ammonium sulfate precipitation, sucrose density gradient centrifugation, and high-pressure liquid chromatography on a Shim pack Diol 300 column. On high-pressure liquid chromatography, most of the beta-galactosidase that comigrated with the sialidase on sucrose density gradient centrifugation was removed. The sialidase was purified 3,600-fold from the preparation obtained by Con A-Sepharose adsorption. The enzyme liberated the sialic acid residues from (alpha 2-3) and (alpha 2-6) sialyllactose, colomic acid, fetuin, and transferrin, but not from bovine submaxillary mucin. The enzyme also hydrolyzed gangliosides GM3, GD1a, and GD1b in the presence of sodium cholate as a detergent, but GM1 and GM2 were less susceptible to the enzyme. The optimum pHs for 4-methylumbelliferyl-N-acetylneuraminate, sialyllactose, fetuin, and GM3 lay between 4.0 and 5.0.

Chromatography, Affinity↗

PubMed1988

Properties of a novel GTP-binding protein which is associated with soluble phosphoinositides-specific phospholipase C.

Recently we demonstrated the presence in calf thymocytes of a GTP-binding protein (G-protein) composed of three polypeptides, 54, 41, and 27 kDa, which was physically and functionally associated with a soluble phosphoinositides-specific phospholipase C (PI-phospholipase C). The properties of this G protein were further investigated with the following results. 1) In addition to the ability to bind [35S]guanosine-5'-[gamma-thio]triphosphate (GTP gamma S), the G-protein exhibited GTPase activity, which was enhanced by Mg2+, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol, but inhibited by sodium cholate, GTP gamma S and F-.2) The 54-kDa polypeptide was ADP-ribosylated by pertussis toxin and also by endogenous membrane-bound ADP-ribosyltransferase, but none of these three polypeptides was ADP-ribosylated by cholera toxin. 3) The G-protein did not cross-react with either anti-rat brain alpha 1 (alpha-subunit of inhibitory G-protein, G1), alpha 0 (alpha-subunit of other G1-like G-protein, G0) or beta gamma antibodies. 4) Incubation of this G Protein with GTP gamma S caused dissociation of the three polypeptides. 5) The 27 kDa polypeptide showed GTP-binding activity and enhanced the phosphatidylinositol 4,5-bisphosphate hydrolysis by purified PI-phospholipase C. These results suggest that the PI-phospholipase C-associated G-protein in calf thymocytes may be a novel one and that it is involved in the regulation of PI-phospholipase C activity.

Adenosine Diphosphate Ribose↗

PubMed1988

Catalytic properties of cytochrome c oxidase purified from Nitrosomonas europaea.

Cytochrome c oxidase of Nitrosomonas europaea reacts with not only the native cytochrome c (N. europaea cytochrome c-552) but also horse and yeast cytochromes c. The effects on its reactivity of various reagents were very different between the reactions with the native and eukaryotic cytochromes c as the electron donors. The oxidation of eukaryotic ferrocytochrome c by the oxidase was activated by addition of anionic detergents such as sodium dodecyl sulfate and sodium cholate, and anionic phospholipids such as cardiolipin, phosphatidylserine, phosphatidylinositol, and phosphatidylethanolamine, while the reaction was not activated by Triton X-100, Tween 20, or phosphatidylcholine. However, the reaction with the native cytochrome c of the enzyme was hardly affected by any of the detergents and phospholipids mentioned above, while it was activated by the presence of poly-L-lysine.

Catalysis↗

PubMed1988

Immunoassay for the beta gamma subunits of GTP-binding proteins and their regional distribution in bovine brain.

Antibodies were raised in rabbits against the beta gamma subunits of bovine brain GTP-binding proteins, and were purified with a beta gamma-coupled Sepharose column. Purified antibodies reacted strongly with 36,000-dalton beta subunit and slightly with 35,000-dalton beta and gamma subunits, but not with other proteins in an immunoblot assay. Using these purified antibodies, a sensitive enzyme immunoassay method for the quantification of brain beta gamma was developed. The assay system consisted of polystyrene balls with immobilized antibody F(ab')2 fragments and the same antibody Fab' fragments labeled with beta-D-galactosidase from Escherichia coli. The minimum detection limit of the assay was 3 fmol, or 130 pg. Samples from various regions of bovine brain were solubilized with 2% sodium cholate and 1 M NaCl, and the concentrations of beta gamma were determined. The beta gamma were detected in all the regions, and the highest concentrations were observed in the cerebral cortex and nucleus caudatus. The concentrations of beta gamma were higher than those of alpha subunit of GTP-binding protein, Go, in all the regions.

Animals↗

PubMed1988

Adenosine binding sites of rat pheochromocytoma PC 12 cell membranes: partial characterization and solubilization.

Rat pheochromocytoma PC 12 cell membranes were shown to possess A2-like adenosine binding sites as assessed by using 5'-N-ethylcarboxamide[3H]adenosine [( 3H]NECA). Specific [3H]NECA binding to PC 12 cell membrane at 0 degrees C was saturable and showed a monophasic saturation profile. In contrast, [3H]NECA binding to PC 12 cell membrane at 30 degrees C exhibited a biphasic profile suggesting the presence of two specific binding site. The rank order of potency for inhibition of [3H]NECA binding at 0 degrees C was NECA greater than 2-chloroadenosine greater than 2',5'-dideoxyadenosine greater than isobutylmethylxanthine much greater than phenylisopropyladenosine. These adenosine binding sites were solubilized with sodium cholate and the solubilized portion retained the same ligand binding characteristics as those of the membrane-bound form. Gel filtration experiments indicated an apparent Stokes radius of 6.7 nm for these adenosine binding sites/detergent complexes.

Adenosine↗

PubMed1990

Immunochemical and immunohistochemical localization of the G protein Gi1 in rat central nervous tissues.

Antisera were raised in rabbits against purified alpha subunit of G protein Gi1 (Gi1 alpha) and also against a synthetic decapeptide corresponding to a sequence of Gi1 alpha. Antibodies in both antisera were purified with a Gi1-coupled Sepharose column, but purified anti-Gi1 alpha protein antibodies still reacted equally with both Gi1 alpha and Gi3 alpha, while anti-Gi1 alpha peptide antibodies reacted principally with Gi1 alpha. Using these antibodies, an enzyme immunoassay method for the quantification of Gi1 alpha was developed. The assay system consisted of polystyrene balls with immobilized anti-Gi1 alpha protein antibody F(ab')2 fragments and the anti-Gi1 alpha peptide antibody Fab' fragments labeled with beta-D-galactosidase from Escherichia coli. The minimum detection limit of the assay was 25 fmol of Gi1 alpha, and it did not cross-react with Gi2 alpha, Go alpha, or beta gamma. Samples from various regions of the rat central nervous system were homogenized in a 2% sodium cholate solution, and the concentration of Gi1 alpha in each extract was determined. Gi1 alpha was detected in all the regions, and the highest concentration was found in the olfactory bulb. Immunohistochemical study showed that Gi1 was mainly localized in the neuropil.

Animals↗

PubMed1992

Purification and properties of 4-hydroxybiphenyl UDP-glucuronyltransferase from bovine liver microsomes.

A UDP-glucuronyltransferase isoform glucuronizes phenolic xenobiotics such as 4-nitrophenol, and an isoform glucuronizing 4-hydroxybiphenyl has also been found in rat liver. We purified a UDP-glucuronyltransferase isoform glucuronizing 4-hydroxybiphenyl from bovine liver microsomes by solubilization with 0.7% sodium cholate followed by three column chromatographic separations using DEAE-Toyopearl 650S, UDP-hexanolamine Sepharose 4B, and hydroxyapatite. The purified bovine liver 4-hydroxybiphenyl UDP-glucuronyltransferase (named Bovine 4HBGT) had glucuronidation activities toward 4-hydroxybiphenyl and 4-methylumbelliferone but had little activity toward 4-nitrophenol and 1-naphthol. The apparent molecular mass of Bovine 4HBGT was 54,000 Da on SDS-PAGE, and this was decreased to 50,000 Da by digestion with endo-beta-N-acetylglucosaminidase H. These data suggest that Bovine 4HBGT consists of a 50,000 Da polypeptide and a high mannose type oligosaccharide chain(s) of about 4,000 Da. The NH2-terminal sequence of GT-3 was GKVLVWPVDFSXWINI. These properties of Bovine 4HBGT were very similar to those of rat UDP-glucuronyltransferase glucuronizing xenobiotics. However, the NH2-terminal sequence of Bovine 4HBGT had higher homology with that of rat liver 4-hydroxybiphenyl UDP-glucuronyltransferase than with that of rat liver 4-nitrophenol UDP-glucuronyltransferase.

Amino Acid Sequence↗

PubMed1993

Purification and characterization of two isoforms of serine proteinase from the microsomal membranes of rat liver.

An extensive purification of microsomal serine proteinase was achieved from rat liver microsome membranes solubilized with 1% sodium cholate by a series of column chromatographic steps on hydroxylapatite, DEAE-cellulose, and benzamidine-Sepharose 6B, and polyacrylamide gel electrophoresis (PAGE). In the final step of PAGE, the enzyme was separated into two fractions with slightly different mobilities, designated microsomal serine proteinases 1 (MSP1) and 2 (MSP2). The former was purified about 8,000-fold to apparent homogeneity, and the latter was purified about 800-fold, starting from the sample which had been spontaneously activated after elution from the hydroxylapatite column. Both enzyme fractions showed essentially the same properties, including molecular weight, susceptibility to various proteinase inhibitors and metal ions, specificity of action toward protein substrates with special preference for a basic protein histone as well as toward synthetic substrates, and pH dependence of activity toward a synthetic substrate and two neuropeptides. Taken together with the same behavior on a series of chromatographic steps, the two isoforms are thought to be essentially the same enzyme. Further, the detailed kinetic studies of the enzyme activity, especially of MSP1, toward various synthetic and naturally occurring peptide substrates showed that it was highly specific for basic amino acid pairs, strictly hydrolyzing at the COOH side of arginine residue. These results are consistent with those obtained previously with a partially purified enzyme and establish more definitely and in detail the specificity as well as other molecular and enzymatic properties of the enzyme.

Amino Acid Sequence↗

PubMed1975

Studies on phospholipases from Streptomyces. II. Purification and properties of Streptomyces hachijoensis phospholipase D.

1. Phospholipase D [EC 3.1.4.4] from Streptomyces hachijoensis was purified about 570-fold by column chromatography on DEAE-cellulose and Sephadex G-50 followed by isoelectric focusing. 2. The purified preparation was found to be homogeneous both by immunodiffusion and polyacrylamide disc gel electrophoresis. 3. The isoelectric point was found to be around pH 8.6 and the molecular weight was about 16,000. 4. The enzyme has maximal activity at pH 7.5 at 37 degrees. The optimal temperature is around 50 degrees at pH 7.5, using 20 min incubation. 5. The enzyme was stable at 50 degrees for 90 min. At neutral pH, between 6 and 8, the enzyme retained more than 95% of its activity on 24 hr incubation at 25 degrees. However, the enzyme lost 80% of its activity under the same conditions at pH 4.0. 6. The enzyme was stimulated slightly by Ca2+, Mn2+, and Co2+, and significantly by Triton X-100 and ethyl ether. It was inhibited by Sn2+, Fe2+, Fe3+, Al3+, EDTA, sodium dodecyl sulfate, sodium cholate, and cetylpyridinium chloride. 7. This phospholipase D hydrolyzes phosphatidylethanolamine, phosphatidylcholine, cardiolipin, sphingomyelin, phosphatidylserine, and lysophosphatidylcholine, liberating the corresponding bases. 8. The Km value was 4mM, determined with phosphatidylethanolamine as a substrate.

Aluminum↗

PubMed1975

Studies on phospholipases from Streptomyces. III. Purification and properties of Streptomyces hachijoensis phospholipase C.

1. Phospholipase C [EC 3.1.4.3] found in the growth medium of Streptomyces hachijoensis was purified about sixty-fold by dialysis and column chromatography on Sephadex G-50. 2. The active fraction was separated by isoelectric focusing into two fractions, phospholipase C-I (pI 6.0) and phospholipase C-II (pI 5.6). 3. Both purified phospholipases C were homogeneous by immunodiffusion and were not differentiated as regards antigencity. 4. Phospholipase C-I had maximal activity at pH 8.0 and the optimal temperature was 50degree. Phospholipase C-I was stable at 50degrees for 30 min and was stable at neutral pH. 5. The activity of phospholipase C-I was inhibited by high concentrations of various detergents such as Triton X-100, sodium, cholate, SDS and was also inhibited by Ca2+, Ba2+, Al3+, and EDTA, but was stimulated by Mg2+, and ethyl ether. 6. The Km value of phospholipase C-I was 0.9 mM, using phosphatidylcholine as a substrate. 7. By the gel filtration procedure, the molecular weights of phospholipase C-I and -II were both determined to be 18,000. 8. Phosphatidylcholine, phosphatidylinositol, cardiolipin, sphingomyelin, and lysophosphatidylcholine were hydrolyzed by phospholipase C-I, but phosphatidylethanolamine and phosphatidylserine were hydrolyzed with difficulty under the same conditions, Phospholipase C-I also hydrolyzed phosphatidic acid.

Aluminum↗

PubMed1976

The use of 8-aminooctyl sepharose for the separation of some components of the hepatic microsomal electron transfer system.

Hepatic microsomes from phenobarbital-pretreated rats were treated with sodium cholate in the presence of glycerol and the solubilized proteins were absorbed on a column of 8-aminooctyl derivative of Sepharose 4B. Washing the column stepwise with buffers containing suitable detergents in addition to cholate resulted in the elution of cytochrome P-450, NADH-cytochrome b5 reductase [EC 1.6.2.2], NADPH-cytochrome c reductase [EC 1.6.2.4], and cytochrome b5; the former two enzymes were eluted with Emulgen 913 (a polyoxyethylene nonylphenyl ether), and then the latter two were obtained separately by increasing the concentration of added deoxycholate. Thus, cytochrome P-450, NADPH-cytochrome c reductase, and cytochrome b5 were purified to specific contents (or activities) of 9--10 nmoles per mg of protein, 15-16 units per mg of protein, and nearly 35 nmoles per mg of protein, respectively (about 40--50% pure), in 40--50% yields. Practically no mutual contamination of the three enzymes was detected. Benzphetamine N-demethylation activity could be reconstituted on mixing the cytochrome P-450 and NADPH-cytochrome c reductase preparations in the presence of cholate. NADH-cytochrome C reductase activity could be observed at high efficiency under appropriate conditions in a system containing the cytochrome b5 and NADH-cytochrome b5 reductase preparations. Various derivatives of Sepharose 4B were compared for effectiveness in the separation of the microsomal election transfer enzymes.

Animals↗

PubMed1979

Enzymatic properties of neuraminidases from Arthrobacter ureafaciens.

Neuraminidase I and neuraminidase II from Arthrobacter ureafaciens were characterized. As determined by gel filtration on Ultrogel AcA 44, the molecular weights of neuraminidases I and II were 51,000 and 39,000, respectively. Neuraminidases I and II were similar to each other in their enzymatic properties except for the substrate specificities towards gangliosides and erythrocyte stroma. Their optimal pHs were between 5.0 and 5.5 with N-acetylneuraminosyl-lactose or bovine submaxillary mucin as substrates, but with colominic acid as a substrate, the pH optimum was between 4.3 and 4.5. They were most active around 53 degrees C, were stable between pH 6.0 and 9.0, and were thermostable up to 50 degrees C. They did not require Ca2+ for activity and were not inhibited by EDTA. They were inhibited only slightly or not at all by p-chloromercuribenzoic acid of Hg2+. Both neuraminidases I and II were able to hydrolyze the alpha-ketosidic linkage of N-glycolylneuraminic acid as well as that of N-acetylneuraminic acid, and were able to liberate substantially all of the sialic acid from various kinds of substrates. However, they cleaved only about 50% of the sialic acid from bovine submaxillary mucin. The saponification of bovine submaxillary mucin by mild alkali treatment, on the other hand, resulted in an increased susceptibility to the neuraminidases and brought about the complete liberation of sialic acid. Remarkable differences were observed between neuraminidases I and II as regards substrate specificities on gangliosides; the initial rate of hydrolysis by neuraminidase I was 74 times, and its maximum velocity constant was 91 times those of neuraminidase II. The addition of sodium cholate markedly stimulated the enzymatic hydrolysis of gangliosides, and increased the maximum velocity constant of neuraminidase I twofold and that of neuraminidase II 143-fold. Although neuraminidases I and II were able to hydrolyze (alpha,2-3), (alpha,2-6), and (alpha,2-8) linkages, the initial rate of hydrolysis of N-acetylneuraminosyl-alpha,2-6-lactose was greater than that of the alpha,2-3-isomer.

Arthrobacter↗

PubMed1980

Effects of cholic acid, chenodeoxycholic acid, and their related bile acids on cholesterol, phospholipid, and bile acid levels in serum, liver, bile, and feces of rats.

Effects of sodium cholate, deoxycholate, chenodeoxycholate, and lithocholate on serum and liver cholesterol levels, bile flow, biliary cholesterol, phospholipids, and bile acids, and fecal sterols and bile acids were examined in Wistar strain male rats fed either an ordinary diet or a 2% cholesterol diet. Cholate and deoxycholate increased serum and liver cholesterol levels, serum pre beta-lipoprotein, bile flow, and biliary secretion of cholesterol, phospholipids, and bile acids, but chenodeoxycholate and lithocholate did not. The total amounts of sterols and of bile acids in the feces did not differ between the cholate and the chenodeoxycholate groups. All the bile acids except lithocholate decreased fecal coprostanol when the diet included cholesterol. Cholate and deoxycholate produced similar bile acid compositions in the bile and feces, as was the case between chenodeoxycholate and lithocholate, though chenodeoxycholate slightly increased the amount of muricholic acids, and lithocholate that of hyodeoxycholic acid, in the feces. The effects of cholate and deoxycholate are similar to each other but different from that of chenodeoxycholate or lithocholate in rats. Cholate causes marked accumulation of cholesterol in tissues, increased bile flow and biliary lipid secretion but chenodeoxycholate does not. Cholate is absorbed much more efficiently than chenodeoxycholate.

Animals↗

PubMed1982

Purification and properties of the tightly bound reduced nicotinamide adenine dinucleotide phosphate-adrenodoxin reductase of bovine adrenocortical mitochondria.

Two forms of NADPH-adrenodoxin reductase, tightly and loosely bound forms, were found in bovine adrenocortical mitochondria. The loosely bound NADPH-adrenodoxin reductase was solubilized by ultrasonication and its content was about 65% of the total activity in bovine adrenocortical mitochondria. The tightly bound NADPH-adrenodoxin reductase could not be solubilized by mechanical sonication and required detergent treatment. The tightly bound NADPH-adrenodoxin reductase was purified to homogeneity, judging by sodium dodecyl sulfate (SDS) gel electrophoresis, from bovine adrenocortical mitochondria using sodium cholate solubilization and chromatography on DEAE-Sepharose and 2'5'-ADP-Sepharose columns. Its physicochemical properties were similar to those of the loosely bound form, except for its carbohydrate composition.

Adrenal Cortex↗

PubMed1985

Evidence for involvement of cytochrome P-450-linked oxygenase system in the conversion of C21-steroids to delta 16-C19-steroids catalyzed by pig testicular microsomes.

Formation of androstadienone or androstadienol, a delta 16-C19-steroid, from progesterone or pregnenolone is catalyzed by the so-called delta 16-C19-steroid synthesizing enzyme in the pig testicular microsomes. The enzyme activity was also present in the testicular microsomes prepared from neonatal pig. The enzyme activity was considerably inhibited by CO, and such cytochrome P-450 inhibitors as SU 8000, SU 10603, and metyrapone. delta 16-C19-Steroid synthesizing enzyme activity was extracted from the testicular microsomes by sodium cholate in potassium phosphate buffer, pH 7.4, containing EDTA and dithiothreitol, and the solubilized enzyme activity was partially purified by DEAE-cellulose column chromatography. It was shown by reconstitution of the enzyme activity that delta 16-C19-steroid synthesizing enzyme is a cytochrome P-450-linked oxygenase system dependent on cytochrome P-450-reductase and cytochrome b5. In particular, cytochrome b5 was an essential component for the activity of delta 16-C19-steroid synthesizing enzyme.

Animals↗

PubMed1985

Import and processing of the precursor of cytochrome P-450(SCC) by bovine adrenal cortex mitochondria.

Isolated bovine adrenal cortex mitochondria imported in vitro synthesized pre-P-450(SCC) and processed it to the mature form. Partial radio-sequencing of the processed P-450(SCC) gave a result identical with that for authentic P-450(SCC). Rat liver mitochondria also imported pre-P-450(SCC) and processed it to the mature form, whereas bovine heart mitochondria were unable to import and process pre-P-450(SCC) although both mitochondrial preparations imported and processed pre-adrenodoxin. The pre-P-450(SCC) processing activity of bovine adrenal cortex mitochondria was associated with the matrix side surface of the inner membrane. The processing protease could be solubilized by sodium cholate and partially purified by ammonium sulfate fractionation. The partially purified processing protease cleaved pre-P-450(SCC) at the correct position. It was also active in processing pre-P-450(11 beta) but inactive toward pre-adrenodoxin. Bovine heart mitochondria lacked the processing activity to pre-P-450(SCC). The localization of pre-P-450(SCC) and mature P-450(SCC) in bovine adrenal cortex mitochondria was examined. Mature P-450(SCC) processed by the mitochondria was found associated with the matrix-side surface of the inner membrane, which is the correct location of P-450(SCC) in the cell. In the presence of o-phenanthroline, pre-P-450(SCC) was imported into the organelles without being processed and remained soluble in the matrix. The incorporation of newly processed mature P-450(SCC) into the inner membrane was also observed when pre-P-450(SCC) was incubated with inner membrane vesicles. Mature P-450(SCC) generated in vitro from pre-P-450(SCC) by the partially purified processing protease was incorporated not only into the inner membrane vesicles but also into bovine adrenal cortex microsomes. These findings suggested that the processing of pre-P-450(SCC) occurred prior to the incorporation of mature-P-450(SCC) into the inner membrane.

Adrenal Cortex↗