Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of bifunctional cross-linking reagents on the purified hexameric cytochrome P-450LM2 in an aqueous medium and on the proteoliposomal cytochrome P-450LM2 have been compared. In both cases, cross-linking is shown to result in the appearance of a range of additional protein bands in SDS electrophoretograms. The number and the positions of these bands seem to be similar in the solubilized and in the proteoliposomal cytochromes. No additional bands appear when the purified cytochrome P-450 was pretreated with 0.2%. Emulgen 913, which decomposes cytochrome P-450LM2 hexamers. The results indicate that the membrane-bound cytochrome P-450 can exist in the oligomeric (presumably hexameric) form.
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PMID:Cytochrome P-450LM2 oligomers in proteoliposomes. 226 95

1. Antibodies to mouse liver cytochrome P3-450 (anti-P3-450) and antibodies to rat liver cytochrome P-450d (anti-P-450d-c) both inhibit the O-deethylation of 7-ethoxy-resorufin (ER) in liver microsomes of benzo(a)pyrene-induced (BP) mice but do not inhibit the O-deethylase activity in liver microsomes of BP-induced rats. 2. Anti-P3-450 and anti-P-450d-c inhibit BP hydroxylation in BP-induced mouse liver microsomes by 20%, but they do not inhibit this rection at all in BP-induced rat liver microsomes. 3. Isolated cytochrome P3-450 in a reconstituted monooxygenase system metabolized 7-ER and BP. In contrast, its homologue, cytochrome P-450d, does not metabolize these substrates. The fraction containing cytochrome P1-450 metabolized 7-ER at a low rate and BP at a rate of 3.6 nmol product/min per nmol cytochrome. 4. Western blot analysis with anti-P-450c + d revealed two bands in SDS-PAGE gels containing BP-induced mouse liver microsomes corresponding to cytochrome P1-450, 55.0 kDa, and cytochrome P3-450, 54.5 kDa. There appeared a single band (cytochrome P3-450) in interaction of mouse liver BP-microsomes with anti-P3-450 and anti-P-450d-c.
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PMID:Interspecies features of hepatic cytochromes P450 IA1 and P450 IA2 in rodents. 227 12

Experimental hepatomas induced with 5,9-dimethyldibenzo[c,g]carbazole in female XVIInc/Z mice display a strong microsomal steroid 15 alpha-hydroxylation activity. A cytochrome P-450 isoenzyme (cytochrome P-450tu), specific for this activity, has been isolated by an HPLC derived method using various Fractogel TSK and hydroxyapatite supports. On SDS polyacrylamide gel electrophoresis the purified protein appeared as one major band with an apparent Mr of 50,000. Its specific cytochrome P-450 content was 7.55 nmol/mg protein. As deduced from the visible spectrum, the heme iron of the isolated P-450tu was to 72% in the high-spin state. The CO-bound reduced form showed an absorption maximum at 450 nm. In addition to the stereospecific 15 alpha-hydroxylation of progesterone (2.3 min-1) and testosterone (2.5 min-1), the enzyme catalyzed also 7-ethoxycoumarin O-deethylation, benzphetamine N-demethylation and aniline 4-hydroxylation. Its N-terminal amino-acid sequence (21 residues) was identical to that of cytochrome P-450(15) alpha, isolated by Harada and Negishi from liver microsomes of 129/J mice. P-450tu differed from P-450(15) alpha by its higher molecular weight, its 40-times lower steroid 15 alpha-hydroxylation and its 4-times higher benzphetamine N-demethylation.
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PMID:Isolation and partial characterization of a cytochrome P-450 isoenzyme (cytochrome P-450tu) from mouse liver tumors. 231 13

Rifapentine (R773, DL473) is a long-acting antituberculous drug used in China. In our experiments we have found some manifestations of induction of hepatic mixed function oxidase system in mice following pretreatment with rifapentine or phenobarbital. Both rifapentine and phenobarbital significantly increased the rate of antipyrine and pentobarbital metabolism in vivo. They also increased liver weight, the content of liver microsomal protein and cytochrome P-450, the activity of NADPH-cytochrome C reductase and NADPH oxidase. SDS-polyacylamide gel electrophoresis showed that the relative proportions of some polypeptide bands in mice microsomal fraction were significantly changed following rifapentine or phenobarbital pretreatment. The results indicate that rifapentine, like phenobarbital, is a potent inducer of hepatic mixed function oxidase system in mice and that it should be used carefully in clinical therapy, when combined with other drugs.
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PMID:Inductive effects of rifapentine on mice hepatic mixed function oxidase system. 231 33

Highly specific antibodies to adrenocortical cytochrome P-450scc as well as fragments F1 and F2 representing the N- and C-terminal sequences of the hemoprotein obtained by limited trypsinolysis were raised in rabbits. Antibodies to cytochrome P-450scc as demonstrated by the Ouchterlony diffusion analysis, immunoelectrophoresis and immunoblotting techniques interact with the hemoprotein and both fragments. Antibodies to cytochrome P-450scc fragments interact with the hemoprotein and corresponding antigens, but do not cross-react. To determine the localization of antigenic determinants in the polypeptide chain of cytochrome P-450scc, the interaction of antibodies to the hemoprotein and to its fragments F1 and F2 with limited trypsinolysis products was studied. All antibodies were found to effectively inhibit cholesterol transformation into pregnenolone in a reconstituted system. Using SDS electrophoresis followed by immunoblotting, the cross-reactivity of antibodies to cytochrome P-450scc and to its fragments with microsomal cytochromes P-450scc LM2 and LM4 as well as with mitochondrial cytochrome P-45027 was revealed. This finding testifies to the presence of common antigenic determinants in the hemoproteins.
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PMID:[Immunochemical characteristics of cholesterol-hydroxylating cytochrome P-450. Monospecific antibodies against domains F1 and F2]. 243 43

Three forms of cytochrome P-450, tentatively designated P-450(M-1), P-450(M-2), and P-450(M-3), and one form of cytochrome P-450, P-450(F-1), were purified from the liver microsomes of untreated male and female rats, respectively. Each purified form of the cytochrome showed a single protein band on SDS-polyacrylamide gel electrophoresis, and gave a minimum molecular weight of 51,000 for P-450(M-1), 48,000 for P-450(M-2), 49,000 for P-450(M-3), and 50,000 for P-450(F-1). The carbon monoxide-difference spectra of reduced P-450(M-1), P-450(M-2), P-450(M-3), and P-450(F-1) showed an absorption maximum at 451, 451, 448, and 449 nm, respectively. Judging from the absolute absorption spectra, the four forms of cytochrome P-450 were of low-spin type in the oxidized forms. The antibodies against P-450(M-2) did not crossreact with the other forms in the Ouchterlony double diffusion test, whereas the immunodiffusion test showed immunocrossreactivity between P-450(M-1) and P-450(F-1), P-450(M-1) and P-450(M-3), and P-450(M-3) and P-450(F-1). The NH2-terminal amino acid sequences of the four forms confirmed that they were different molecular species, although significant homology was noticed among P-450(M-1), P-450(M-3), and P-450(F-1). The quantitation of P-450(M-1) and P-450(F-1) in liver microsomes by quantitative immunoprecipitation confirmed that these two forms of cytochrome P-450 were developmentally induced in male and female rats, respectively. P-450(M-2) was also developmentally induced in male rats. In a reconstituted system containing NADPH and NADPH-cytochrome P-450 reductase, P-450(M-1) oxidized benzphetamine at a high rate, whereas the other forms had low activity toward benzphetamine. None of the four forms showed high activity toward benzo(a)pyrene. P-450(M-1) catalyzed the hydroxylation testosterone at the 16 alpha and 2 alpha positions, whereas P-450(M-2) catalyzed the 15 alpha hydroxylation of the same substrate.
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PMID:Purification and characterization of three male-specific and one female-specific forms of cytochrome P-450 from rat liver microsomes. 243 73

Plastocyanin was purified from a multicellular, marine green alga, Ulva arasakii, by conventional methods to homogeneity. The oxidized plastocyanin showed absorption maxima at 252, 276.8, 460, 595.3, and 775 nm, and shoulders at 259, 265, 269, and 282.5 nm; the ratio A276.8/A595.3 was 1.5. The midpoint redox potential was determined to be 0.356 V at pH 7.0 with a ferri- and ferrocyanide system. The molecular weight was estimated to be 10,200 and 11,000 by SDS-PAGE and by gel filtration, respectively. U. arasakii also has a small amount of cytochrome c6, like Enteromorpha prolifera. The amino acid sequence of U. arasakii plastocyanin was determined by Edman degradation and by carboxypeptidase digestion of the plastocyanin, six tryptic peptides, and five staphylococcal protease peptides. The plastocyanin contained 98 amino acid residues, giving a molecular weight of 10,236 including one copper atom. The complete sequence is as follows: AQIVKLGGDDGALAFVPSKISVAAGEAIEFVNNAGFPHNIVFDEDAVPAGVDADAISYDDYLNSKGETV VRKLSTPGVY G VYCEPHAGAGMKMTITVQ. The sequence of U. arasakii plastocyanin is closet to that of the E. prolifera protein (85% homology). A phylogenetic tree of five algal and two higher plant plastocyanins was constructed by comparing the amino acid differences. The branching order is considered to be as follows: a blue-green alga, unicellular green algae, multicellular green algae, and higher plants.
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PMID:Some properties and amino acid sequence of plastocyanin from a green alga, Ulva arasakii. 250 42

Confluent human endometrial stromal cells were cultured in medium with no hormone or supplemented with medroxyprogesterone acetate (MPA), estradiol (E2), and porcine relaxin (RLX) for 5 days. These stromal cells were then labeled with [35S]methionine for 3 h. The radioactive proteins in the particulate fraction of cell homogenate were extracted by detergent and incubated with antisera to purified placental aromatase cytochrome P-450 (P-450arom) and NADPH-cytochrome P-450 reductase to isolate the radio-labeled aromatase enzyme components. Analysis of the radio-labeled protein, isolated by antibody to the cytochrome P-450arom from different preparations (P45FBIII or R-8-2) showed a major band at molecular weight 54k on SDS polyacrylamide gel electrophoresis (SDS-PAGE). The intensity of 54k band was stronger in hormone treated stromal cells than that of control in parallel with the increase of aromatase activity. The radio-labeled protein isolated by anti-NADPH cytochrome P-450 reductase, REDFBIV, showed a major band at the molecular weight 73k on SDS-PAGE with comparable intensity in control and hormone treated samples. Thus, the apparent molecular weights of endometrial cytochrome P-450arom and cytochrome P-450 reductase were identical to placental aromatase enzyme system. When a secretory endometrium and a decidua were labeled with [35S]methionine, the cytochrome P-450arom was detected only in the decidua. NADPH cytochrome P-450 reductase was detected both in the endometrium and the decidua. These results show that antisera to placental aromatase enzyme system cross reacts with the endometrial aromatase enzyme components. The synthesis of cytochrome P-450arom was stimulated by MPA, E2 and RLX while the synthesis of the NADPH-cytochrome P-450 reductase aromatase component was not affected by the hormone.
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PMID:Immunologic identification of the aromatase enzyme system in human endometrium. 253 8

A soluble red band fraction was obtained from Leishmania tarentolae cells by sucrose gradient sedimentation of a Triton X-100 lysate. Spectral analysis indicated that cytochrome b was present in the red band: the reduced minus oxidized difference spectra revealed absorption maxima at 562,527, and 431 nm at room temperature and 562, 530, and 422 nm at 77K. In addition, a 28-kDa protein was identified in this fraction which retained heme-associated peroxidase activity even after denaturation on SDS-polyacrylamide gels. The amino acid composition of this protein showed a strong similarity to cytochrome c1 of both bovine and yeast.
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PMID:Characterization of a protein fraction containing cytochromes b and c1 from mitochondria of Leishmania tarentolae. 254 79

Soluble cytochrome c-552 was purified from Thiobacillus ferrooxidans to an electrophoretically homogeneous state. The cytochrome showed absorption peaks at 276, 411 and 523 nm in the oxidized form and peaks at 315, 417, 523 and 552 nm in the reduced form. The molecular weight of the cytochrome was estimated to be 13,800 on the basis of the amino acid composition and heme content, and 14,000 from SDS-polyacrylamide gel electrophoresis analysis. Its midpoint redox potential at pH 7.0 was determined to be +0.36 V. The N-terminal amino acid sequence of the cytochrome was determined as follows: A-G-G-A-G-G-P-A-P-Y-R-I-S-?-D-?-M-V-?-S-G-M-P-G-. Ferrocytochrome c-552 was oxidized by the membrane fraction of T. ferrooxidans, and the oxidation rate was more rapid at pH 3.0 than at pH 6.5. Ferricytochrome c-552 was reduced by Fe(II)-cytochrome c oxidoreductase with Fe2+ at pH 3.5, while horse ferricytochrome c was not reduced by the enzyme under the same reaction conditions.
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PMID:Thiobacillus ferrooxidans cytochrome c-552: purification and some of its molecular features. 255 85


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