HUMAN TACE MUTANT G1234
[ACE_HUMAN] Genetic variations in ACE may be a cause of susceptibility to ischemic stroke (ISCHSTR) [MIM:601367]; also known as cerebrovascular accident or cerebral infarction. A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. Ischemic strokes, resulting from vascular occlusion, is considered to be a highly complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors. Defects in ACE are a cause of renal tubular dysgenesis (RTD) [MIM:267430]. RTD is an autosomal recessive severe disorder of renal tubular development characterized by persistent fetal anuria and perinatal death, probably due to pulmonary hypoplasia from early-onset oligohydramnios (the Potter phenotype). Genetic variations in ACE are associated with susceptibility to microvascular complications of diabetes type 3 (MVCD3) [MIM:612624]. These are pathological conditions that develop in numerous tissues and organs as a consequence of diabetes mellitus. They include diabetic retinopathy, diabetic nephropathy leading to end-stage renal disease, and diabetic neuropathy. Diabetic retinopathy remains the major cause of new-onset blindness among diabetic adults. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis. Defects in ACE are a cause of susceptibility to intracerebral hemorrhage (ICH) [MIM:614519]. A pathological condition characterized by bleeding into one or both cerebral hemispheres including the basal ganglia and the cerebral cortex. It is often associated with hypertension and craniocerebral trauma. Intracerebral bleeding is a common cause of stroke.
[ACE_HUMAN] Converts angiotensin I to angiotensin II by release of the terminal His-Leu, this results in an increase of the vasoconstrictor activity of angiotensin. Also able to inactivate bradykinin, a potent vasodilator. Has also a glycosidase activity which releases GPI-anchored proteins from the membrane by cleaving the mannose linkage in the GPI moiety.
Publication Abstract from PubMed
Human angiotensin-converting enzyme is an important drug target for which little structural information has been available until recent years. The slow progress in obtaining a crystal structure was due to the problem of surface glycosylation, a difficulty that has thus far been overcome by the use of a glucosidase-1 inhibitor in the tissue culture medium. However, the prohibitive cost of these inhibitors and incomplete glucosidase inhibition makes alternative routes to minimizing the N-glycan heterogeneity desirable. Here, glycosylation in the testis isoform (tACE) has been reduced by Asn-Gln point mutations at N-glycosylation sites, and the crystal structures of mutants having two and four intact sites have been solved to 2.0 A and 2.8 A, respectively. Both mutants show close structural identity with the wild-type. A hinge mechanism is proposed for substrate entry into the active cleft, based on homology to human ACE2 at the levels of sequence and flexibility. This is supported by normal-mode analysis that reveals intrinsic flexibility about the active site of tACE. Subdomain II, containing bound chloride and zinc ions, is found to have greater stability than subdomain I in the structures of three ACE homologues. Crystallizable glycosylation mutants open up new possibilities for cocrystallization studies to aid the design of novel ACE inhibitors.
Structure of testis ACE glycosylation mutants and evidence for conserved domain movement.,Watermeyer JM, Sewell BT, Schwager SL, Natesh R, Corradi HR, Acharya KR, Sturrock ED Biochemistry. 2006 Oct 24;45(42):12654-63. PMID:17042482
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.