The kinetic mechanism of the hypothalamic progesterone 5α-reductase
The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double recipro...
Ausführliche Beschreibung
Gespeichert in:
| Autor*in: |
|---|
| Format: |
E-Artikel |
|---|---|
| Sprache: |
Englisch |
| Erschienen: |
1989 |
|---|
| Reproduktion: |
Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 |
|---|---|
| Übergeordnetes Werk: |
in: Journal of Steroid Biochemistry - Amsterdam : Elsevier, 32(1989), 2, Seite 283-289 |
| Übergeordnetes Werk: |
volume:32 ; year:1989 ; number:2 ; pages:283-289 |
| Links: |
|---|
| Katalog-ID: |
NLEJ186365365 |
|---|
| LEADER | 01000caa a22002652 4500 | ||
|---|---|---|---|
| 001 | NLEJ186365365 | ||
| 003 | DE-627 | ||
| 005 | 20210707043410.0 | ||
| 007 | cr uuu---uuuuu | ||
| 008 | 070506s1989 xx |||||o 00| ||eng c | ||
| 035 | |a (DE-627)NLEJ186365365 | ||
| 035 | |a (DE-599)GBVNLZ186365365 | ||
| 040 | |a DE-627 |b ger |c DE-627 |e rakwb | ||
| 041 | |a eng | ||
| 245 | 1 | 4 | |a The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| 264 | 1 | |c 1989 | |
| 336 | |a nicht spezifiziert |b zzz |2 rdacontent | ||
| 337 | |a nicht spezifiziert |b z |2 rdamedia | ||
| 338 | |a nicht spezifiziert |b zu |2 rdacarrier | ||
| 520 | |a The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. | ||
| 533 | |f Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 | ||
| 700 | 1 | |a Campbell, J.S. |4 oth | |
| 700 | 1 | |a Karavolas, H.J. |4 oth | |
| 773 | 0 | 8 | |i in |t Journal of Steroid Biochemistry |d Amsterdam : Elsevier |g 32(1989), 2, Seite 283-289 |w (DE-627)NLEJ18527725X |w (DE-600)2198730-0 |x 0022-4731 |7 nnns |
| 773 | 1 | 8 | |g volume:32 |g year:1989 |g number:2 |g pages:283-289 |
| 856 | 4 | 0 | |u http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 |
| 912 | |a GBV_USEFLAG_H | ||
| 912 | |a ZDB-1-SDJ | ||
| 912 | |a GBV_NL_ARTICLE | ||
| 951 | |a AR | ||
| 952 | |d 32 |j 1989 |e 2 |h 283-289 | ||
| matchkey_str |
article:00224731:1989----::hkntcehnsoteyohlmcrgs |
|---|---|
| hierarchy_sort_str |
1989 |
| publishDate |
1989 |
| allfields |
(DE-627)NLEJ186365365 (DE-599)GBVNLZ186365365 DE-627 ger DE-627 rakwb eng The kinetic mechanism of the hypothalamic progesterone 5α-reductase 1989 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 Campbell, J.S. oth Karavolas, H.J. oth in Journal of Steroid Biochemistry Amsterdam : Elsevier 32(1989), 2, Seite 283-289 (DE-627)NLEJ18527725X (DE-600)2198730-0 0022-4731 nnns volume:32 year:1989 number:2 pages:283-289 http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 GBV_USEFLAG_H ZDB-1-SDJ GBV_NL_ARTICLE AR 32 1989 2 283-289 |
| spelling |
(DE-627)NLEJ186365365 (DE-599)GBVNLZ186365365 DE-627 ger DE-627 rakwb eng The kinetic mechanism of the hypothalamic progesterone 5α-reductase 1989 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 Campbell, J.S. oth Karavolas, H.J. oth in Journal of Steroid Biochemistry Amsterdam : Elsevier 32(1989), 2, Seite 283-289 (DE-627)NLEJ18527725X (DE-600)2198730-0 0022-4731 nnns volume:32 year:1989 number:2 pages:283-289 http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 GBV_USEFLAG_H ZDB-1-SDJ GBV_NL_ARTICLE AR 32 1989 2 283-289 |
| allfields_unstemmed |
(DE-627)NLEJ186365365 (DE-599)GBVNLZ186365365 DE-627 ger DE-627 rakwb eng The kinetic mechanism of the hypothalamic progesterone 5α-reductase 1989 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 Campbell, J.S. oth Karavolas, H.J. oth in Journal of Steroid Biochemistry Amsterdam : Elsevier 32(1989), 2, Seite 283-289 (DE-627)NLEJ18527725X (DE-600)2198730-0 0022-4731 nnns volume:32 year:1989 number:2 pages:283-289 http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 GBV_USEFLAG_H ZDB-1-SDJ GBV_NL_ARTICLE AR 32 1989 2 283-289 |
| allfieldsGer |
(DE-627)NLEJ186365365 (DE-599)GBVNLZ186365365 DE-627 ger DE-627 rakwb eng The kinetic mechanism of the hypothalamic progesterone 5α-reductase 1989 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 Campbell, J.S. oth Karavolas, H.J. oth in Journal of Steroid Biochemistry Amsterdam : Elsevier 32(1989), 2, Seite 283-289 (DE-627)NLEJ18527725X (DE-600)2198730-0 0022-4731 nnns volume:32 year:1989 number:2 pages:283-289 http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 GBV_USEFLAG_H ZDB-1-SDJ GBV_NL_ARTICLE AR 32 1989 2 283-289 |
| allfieldsSound |
(DE-627)NLEJ186365365 (DE-599)GBVNLZ186365365 DE-627 ger DE-627 rakwb eng The kinetic mechanism of the hypothalamic progesterone 5α-reductase 1989 nicht spezifiziert zzz rdacontent nicht spezifiziert z rdamedia nicht spezifiziert zu rdacarrier The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 Campbell, J.S. oth Karavolas, H.J. oth in Journal of Steroid Biochemistry Amsterdam : Elsevier 32(1989), 2, Seite 283-289 (DE-627)NLEJ18527725X (DE-600)2198730-0 0022-4731 nnns volume:32 year:1989 number:2 pages:283-289 http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 GBV_USEFLAG_H ZDB-1-SDJ GBV_NL_ARTICLE AR 32 1989 2 283-289 |
| language |
English |
| source |
in Journal of Steroid Biochemistry 32(1989), 2, Seite 283-289 volume:32 year:1989 number:2 pages:283-289 |
| sourceStr |
in Journal of Steroid Biochemistry 32(1989), 2, Seite 283-289 volume:32 year:1989 number:2 pages:283-289 |
| format_phy_str_mv |
Article |
| institution |
findex.gbv.de |
| isfreeaccess_bool |
false |
| container_title |
Journal of Steroid Biochemistry |
| authorswithroles_txt_mv |
Campbell, J.S. @@oth@@ Karavolas, H.J. @@oth@@ |
| publishDateDaySort_date |
1989-01-01T00:00:00Z |
| hierarchy_top_id |
NLEJ18527725X |
| id |
NLEJ186365365 |
| language_de |
englisch |
| fullrecord |
<?xml version="1.0" encoding="UTF-8"?><collection xmlns="http://www.loc.gov/MARC21/slim"><record><leader>01000caa a22002652 4500</leader><controlfield tag="001">NLEJ186365365</controlfield><controlfield tag="003">DE-627</controlfield><controlfield tag="005">20210707043410.0</controlfield><controlfield tag="007">cr uuu---uuuuu</controlfield><controlfield tag="008">070506s1989 xx |||||o 00| ||eng c</controlfield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-627)NLEJ186365365</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-599)GBVNLZ186365365</subfield></datafield><datafield tag="040" ind1=" " ind2=" "><subfield code="a">DE-627</subfield><subfield code="b">ger</subfield><subfield code="c">DE-627</subfield><subfield code="e">rakwb</subfield></datafield><datafield tag="041" ind1=" " ind2=" "><subfield code="a">eng</subfield></datafield><datafield tag="245" ind1="1" ind2="4"><subfield code="a">The kinetic mechanism of the hypothalamic progesterone 5α-reductase</subfield></datafield><datafield tag="264" ind1=" " ind2="1"><subfield code="c">1989</subfield></datafield><datafield tag="336" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">zzz</subfield><subfield code="2">rdacontent</subfield></datafield><datafield tag="337" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">z</subfield><subfield code="2">rdamedia</subfield></datafield><datafield tag="338" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">zu</subfield><subfield code="2">rdacarrier</subfield></datafield><datafield tag="520" ind1=" " ind2=" "><subfield code="a">The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone.</subfield></datafield><datafield tag="533" ind1=" " ind2=" "><subfield code="f">Elsevier Journal Backfiles on ScienceDirect 1907 - 2002</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Campbell, J.S.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Karavolas, H.J.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="773" ind1="0" ind2="8"><subfield code="i">in</subfield><subfield code="t">Journal of Steroid Biochemistry</subfield><subfield code="d">Amsterdam : Elsevier</subfield><subfield code="g">32(1989), 2, Seite 283-289</subfield><subfield code="w">(DE-627)NLEJ18527725X</subfield><subfield code="w">(DE-600)2198730-0</subfield><subfield code="x">0022-4731</subfield><subfield code="7">nnns</subfield></datafield><datafield tag="773" ind1="1" ind2="8"><subfield code="g">volume:32</subfield><subfield code="g">year:1989</subfield><subfield code="g">number:2</subfield><subfield code="g">pages:283-289</subfield></datafield><datafield tag="856" ind1="4" ind2="0"><subfield code="u">http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">GBV_USEFLAG_H</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">ZDB-1-SDJ</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">GBV_NL_ARTICLE</subfield></datafield><datafield tag="951" ind1=" " ind2=" "><subfield code="a">AR</subfield></datafield><datafield tag="952" ind1=" " ind2=" "><subfield code="d">32</subfield><subfield code="j">1989</subfield><subfield code="e">2</subfield><subfield code="h">283-289</subfield></datafield></record></collection>
|
| series2 |
Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 |
| ppnlink_with_tag_str_mv |
@@773@@(DE-627)NLEJ18527725X |
| format |
electronic Article |
| delete_txt_mv |
keep |
| collection |
NL |
| remote_str |
true |
| illustrated |
Not Illustrated |
| issn |
0022-4731 |
| topic_title |
The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| format_facet |
Elektronische Aufsätze Aufsätze Elektronische Ressource |
| format_main_str_mv |
Text Zeitschrift/Artikel |
| carriertype_str_mv |
zu |
| author2_variant |
j c jc h k hk |
| hierarchy_parent_title |
Journal of Steroid Biochemistry |
| hierarchy_parent_id |
NLEJ18527725X |
| hierarchy_top_title |
Journal of Steroid Biochemistry |
| isfreeaccess_txt |
false |
| familylinks_str_mv |
(DE-627)NLEJ18527725X (DE-600)2198730-0 |
| title |
The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| spellingShingle |
The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| ctrlnum |
(DE-627)NLEJ186365365 (DE-599)GBVNLZ186365365 |
| title_full |
The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| journal |
Journal of Steroid Biochemistry |
| journalStr |
Journal of Steroid Biochemistry |
| lang_code |
eng |
| isOA_bool |
false |
| recordtype |
marc |
| publishDateSort |
1989 |
| contenttype_str_mv |
zzz |
| container_start_page |
283 |
| container_volume |
32 |
| format_se |
Elektronische Aufsätze |
| title_sort |
kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| title_auth |
The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| abstract |
The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. |
| abstractGer |
The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. |
| abstract_unstemmed |
The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone. |
| collection_details |
GBV_USEFLAG_H ZDB-1-SDJ GBV_NL_ARTICLE |
| container_issue |
2 |
| title_short |
The kinetic mechanism of the hypothalamic progesterone 5α-reductase |
| url |
http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3 |
| remote_bool |
true |
| author2 |
Campbell, J.S. Karavolas, H.J. |
| author2Str |
Campbell, J.S. Karavolas, H.J. |
| ppnlink |
NLEJ18527725X |
| mediatype_str_mv |
z |
| isOA_txt |
false |
| hochschulschrift_bool |
false |
| author2_role |
oth oth |
| up_date |
2024-07-06T06:43:41.906Z |
| _version_ |
1803810999534354432 |
| fullrecord_marcxml |
<?xml version="1.0" encoding="UTF-8"?><collection xmlns="http://www.loc.gov/MARC21/slim"><record><leader>01000caa a22002652 4500</leader><controlfield tag="001">NLEJ186365365</controlfield><controlfield tag="003">DE-627</controlfield><controlfield tag="005">20210707043410.0</controlfield><controlfield tag="007">cr uuu---uuuuu</controlfield><controlfield tag="008">070506s1989 xx |||||o 00| ||eng c</controlfield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-627)NLEJ186365365</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-599)GBVNLZ186365365</subfield></datafield><datafield tag="040" ind1=" " ind2=" "><subfield code="a">DE-627</subfield><subfield code="b">ger</subfield><subfield code="c">DE-627</subfield><subfield code="e">rakwb</subfield></datafield><datafield tag="041" ind1=" " ind2=" "><subfield code="a">eng</subfield></datafield><datafield tag="245" ind1="1" ind2="4"><subfield code="a">The kinetic mechanism of the hypothalamic progesterone 5α-reductase</subfield></datafield><datafield tag="264" ind1=" " ind2="1"><subfield code="c">1989</subfield></datafield><datafield tag="336" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">zzz</subfield><subfield code="2">rdacontent</subfield></datafield><datafield tag="337" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">z</subfield><subfield code="2">rdamedia</subfield></datafield><datafield tag="338" ind1=" " ind2=" "><subfield code="a">nicht spezifiziert</subfield><subfield code="b">zu</subfield><subfield code="2">rdacarrier</subfield></datafield><datafield tag="520" ind1=" " ind2=" "><subfield code="a">The kinetic mechanism of the hypothalamic NADPH-linked progesterone 5α-reductase from female rats was determined to be equilibrium ordered sequential by initial velocity, product inhibition and dead-end inhibition studies. Analysis of the initial velocity data resulted in intersecting double reciprocal plots indicating a sequential mechanism (apparent K"m (progesterone) = 95.4 +/- 4.5 nM; apparent K"i"a (NADPH) = 9.9 +/- 0.7+/-M). The plot of l/v vs l/progesterone intersected on the ordinale which is consistent with an equilibrium ordered mechanism. Ordered addition of the substrates was also supported by product inhibition studies with NADP versus NADPH and NADP versus progesterone. NADP is a competitive inhibitor versus NADPH (apparent K"i"s = 4.3 +/- 1.3μM) and a noncompetitive inhibitor versus progesterone (apparent K"i"s = 31.9 +/- 1.4μM and apparent K"i"i = 145.4 +/- 15.5μM). These inhibition patterns show that NADPH binds prior to progesterone. Taken together, these analyses indicate that the cofactor, NADPH, binds to the enzyme in rapid equilibrium and preferentially precedes the binding of progesterone.</subfield></datafield><datafield tag="533" ind1=" " ind2=" "><subfield code="f">Elsevier Journal Backfiles on ScienceDirect 1907 - 2002</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Campbell, J.S.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Karavolas, H.J.</subfield><subfield code="4">oth</subfield></datafield><datafield tag="773" ind1="0" ind2="8"><subfield code="i">in</subfield><subfield code="t">Journal of Steroid Biochemistry</subfield><subfield code="d">Amsterdam : Elsevier</subfield><subfield code="g">32(1989), 2, Seite 283-289</subfield><subfield code="w">(DE-627)NLEJ18527725X</subfield><subfield code="w">(DE-600)2198730-0</subfield><subfield code="x">0022-4731</subfield><subfield code="7">nnns</subfield></datafield><datafield tag="773" ind1="1" ind2="8"><subfield code="g">volume:32</subfield><subfield code="g">year:1989</subfield><subfield code="g">number:2</subfield><subfield code="g">pages:283-289</subfield></datafield><datafield tag="856" ind1="4" ind2="0"><subfield code="u">http://linkinghub.elsevier.com/retrieve/pii/0022-4731(89)90265-3</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">GBV_USEFLAG_H</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">ZDB-1-SDJ</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">GBV_NL_ARTICLE</subfield></datafield><datafield tag="951" ind1=" " ind2=" "><subfield code="a">AR</subfield></datafield><datafield tag="952" ind1=" " ind2=" "><subfield code="d">32</subfield><subfield code="j">1989</subfield><subfield code="e">2</subfield><subfield code="h">283-289</subfield></datafield></record></collection>
|
| score |
7.400298 |