Trichodiene Synthase. Stereochemical Studies of the Cryptic Allylic Diphosphate Isomerase Activity Using an Anomalous Substrate

1994 ◽  
Vol 59 (19) ◽  
pp. 5794-5798 ◽  
Author(s):  
David E. Cane ◽  
Guohan Yang
Keyword(s):  
Isomerase Activity ◽  
Trichodiene Synthase

Studies of the cryptic allylic pyrophosphate isomerase activity of trichodiene synthase using the anomalous substrate 6,7-dihydrofarnesyl pyrophosphate

Biochemistry ◽  
1990 ◽  
Vol 29 (23) ◽  
pp. 5476-5490 ◽  
Author(s):  
David E. Cane ◽  
John L. Pawlak ◽  
R. Marthinus Horak ◽  
Thomas M. Hohn
Keyword(s):  
Isomerase Activity ◽  
Trichodiene Synthase

Updated understanding of platelets in thrombosis and hemostasis: the roles of integrin PSI domains and their potential as therapeutic targets

2020 ◽  
Vol 20 ◽  
Author(s):  
Daniel Thomas MacKeigan ◽  
Tiffany Ni ◽  
Chuanbin Shen ◽  
Tyler William Stratton ◽  
Wenjing Ma ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Platelet Adhesion ◽  
Adaptive Mechanism ◽  
Dynamic Interactions ◽  
Surface Receptors ◽  
Isomerase Activity ◽  
Pathological Conditions ◽  
Fibrinogen Binding ◽  
Immune Mediated ◽  
Novel Target

: Platelets are small blood cells known primarily for their ability to adhere and aggregate at injured vessels to arrest bleeding. However, when triggered under pathological conditions, the same adaptive mechanism of platelet adhesion and aggregation may cause thrombosis, a primary cause of heart attack and stroke. Over recent decades, research has made considerable progress in uncovering the intricate and dynamic interactions that regulate these processes. Integrins are heterodimeric cell surface receptors expressed on all metazoan cells that facilitate cell adhesion, movement, and signaling, to drive biological and pathological processes such as thrombosis and hemostasis. Recently, our group discovered that the plexinsemaphorin-integrin (PSI) domains of the integrin β subunits exert endogenous thiol isomerase activity derived from their two highly conserved CXXC active site motifs. Given the importance of redox reactions in integrin activation and its location in the knee region, this PSI domain activity may be critically involved in facilitating the interconversions between integrin conformations. Our monoclonal antibodies against the β3 PSI domain inhibited its thiol isomerase activity and proportionally attenuated fibrinogen binding and platelet aggregation. Notably, these antibodies inhibited thrombosis without significantly impairing hemostasis or causing platelet clearance. In this review, we will update mechanisms of thrombosis and hemostasis including platelet versatilities and immune-mediated thrombocytopenia, discuss critical contributions of the newly discovered PSI domain thiol isomerase activity, and its potential as a novel target for anti-thrombotic therapies and beyond.

Probing the structural determinants of a catalytic RNA with isomerase activity

1995 ◽  
Vol 117 (40) ◽  
pp. 10145-10146 ◽  
Author(s):  
James R. Prudent ◽  
Joanna Staunton ◽  
Peter G. Schultz
Keyword(s):  
Catalytic Rna ◽  
Structural Determinants ◽  
Isomerase Activity

scholarly journals Inhibition of thiol isomerase activity diminishes endothelial activation of plasminogen, but not of protein C

2015 ◽  
Vol 135 (4) ◽  
pp. 748-753 ◽  
Author(s):  
C.L. Smith ◽  
C.M. Shah ◽  
N. Kamaludin ◽  
M.P. Gordge
Keyword(s):  
Protein C ◽  
Endothelial Activation ◽  
Isomerase Activity

Porcine glutathione transferase Alpha 2-2 is a human GST A3-3 analogue that catalyses steroid double-bond isomerization

2010 ◽  
Vol 431 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Natalia Fedulova ◽  
Françoise Raffalli-Mathieu ◽  
Bengt Mannervik
Keyword(s):  
Double Bond ◽  
Glutathione Transferase ◽  
Biological Species ◽  
Glutathione Transferases ◽  
Special Role ◽  
Primary Role ◽  
The Novel ◽  
Protective Function ◽  
Isomerase Activity

A primary role of GSTs (glutathione transferases) is detoxication of electrophilic compounds. In addition to this protective function, hGST (human GST) A3-3, a member of the Alpha class of soluble GSTs, has prominent steroid double-bond isomerase activity. The isomerase reaction is an obligatory step in the biosynthesis of steroid hormones, indicating a special role of hGST A3-3 in steroidogenic tissues. An analogous GST with high steroid isomerase activity has so far not been found in any other biological species. In the present study, we characterized a Sus scrofa (pig) enzyme, pGST A2-2, displaying high steroid isomerase activity. High levels of pGST A2-2 expression were found in ovary, testis and liver. In its functional properties, other than steroid isomerization, pGST A2-2 was most similar to hGST A3-3. The properties of the novel porcine enzyme lend support to the notion that particular GSTs play an important role in steroidogenesis.

scholarly journals The immunosuppressant SR 31747 blocks cell proliferation by inhibiting a steroid isomerase in Saccharomyces cerevisiae.

1996 ◽  
Vol 16 (6) ◽  
pp. 2719-2727 ◽  
Author(s):  
S Silve ◽  
P Leplatois ◽  
A Josse ◽  
P H Dupuy ◽  
C Lanau ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Proliferation ◽  
Gene Product ◽  
In Vitro Assays ◽  
Gene Products ◽  
Yeast Saccharomyces Cerevisiae ◽  
Isomerase Activity ◽  
Encoding Gene ◽  
Resistant Mutants

SR 31747 is a novel immunosuppressant agent that arrests cell proliferation in the yeast Saccharomyces cerevisiae, SR 31747-treated cells accumulate the same aberrant sterols as those found in a mutant impaired in delta 8- delta 7-sterol isomerase. Sterol isomerase activity is also inhibited by SR 31747 in in vitro assays. Overexpression of the sterol isomerase-encoding gene, ERG2, confers enhanced SR resistance. Cells growing anaerobically on ergosterol-containing medium are not sensitive to SR. Disruption of the sterol isomerase-encoding gene is lethal in cells growing in the absence of exogenous ergosterol, except in SR-resistant mutants lacking either the SUR4 or the FEN1 gene product. The results suggest that sterol isomerase is the target of SR 31747 and that both the SUR4 and FEN1 gene products are required to mediate the proliferation arrest induced by ergosterol depletion.

Immunophilin AtFKBP13 Sustains All Peptidyl−Prolyl Isomerase Activity in the Thylakoid Lumen fromArabidopsis thalianaDeficient in AtCYP20-2†

Biochemistry ◽  
2007 ◽  
Vol 46 (33) ◽  
pp. 9432-9442 ◽  
Author(s):  
Anna Edvardsson ◽  
Alexey Shapiguzov ◽  
Ulrika A. Petersson ◽  
Wolfgang P. Schröder ◽  
Alexander V. Vener
Keyword(s):  
Prolyl Isomerase ◽  
Peptidyl Prolyl Isomerase ◽  
Thylakoid Lumen ◽  
Isomerase Activity
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