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Bae YS, Yoon SH, Kim YS, Oh SP, Song WS, Cha JH, Kim MH. Suppression of exaggerated NMDAR activity by memantine treatment ameliorates neurological and behavioral deficits in aminopeptidase P1-deficient mice. EXPERIMENTAL & MOLECULAR MEDICINE 2022; 54:1109-1124. [PMID: 35922532 PMCID: PMC9440093 DOI: 10.1038/s12276-022-00818-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 11/25/2022]
Abstract
Inborn errors of metabolism (IEMs) are common causes of neurodevelopmental disorders, including microcephaly, hyperactivity, and intellectual disability. However, the synaptic mechanisms of and pharmacological interventions for the neurological complications of most IEMs are unclear. Here, we report that metabolic dysfunction perturbs neuronal NMDA receptor (NMDAR) homeostasis and that the restoration of NMDAR signaling ameliorates neurodevelopmental and cognitive deficits in IEM model mice that lack aminopeptidase P1. Aminopeptidase P1-deficient (Xpnpep1–/–) mice, with a disruption of the proline-specific metalloprotease gene Xpnpep1, exhibit hippocampal neurodegeneration, behavioral hyperactivity, and impaired hippocampus-dependent learning. In this study, we found that GluN1 and GluN2A expression, NMDAR activity, and the NMDAR-dependent long-term potentiation (LTP) of excitatory synaptic transmission were markedly enhanced in the hippocampi of Xpnpep1–/– mice. The exaggerated NMDAR activity and NMDAR-dependent LTP were reversed by the NMDAR antagonist memantine. A single administration of memantine reversed hyperactivity in adult Xpnpep1–/– mice without improving learning and memory. Furthermore, chronic administration of memantine ameliorated hippocampal neurodegeneration, hyperactivity, and impaired learning and memory in Xpnpep1–/– mice. In addition, abnormally enhanced NMDAR-dependent LTP and NMDAR downstream signaling in the hippocampi of Xpnpep1–/– mice were reversed by chronic memantine treatment. These results suggest that the metabolic dysfunction caused by aminopeptidase P1 deficiency leads to synaptic dysfunction with excessive NMDAR activity, and the restoration of synaptic function may be a potential therapeutic strategy for the treatment of neurological complications related to IEMs. Addressing neurological symptoms may offer new treatments for inborn errors of metabolism (IEMs) affecting neurodevelopment. In such IEMs, mutation of an enzyme disrupts a metabolic pathway, causing buildup or lack of key molecules, with symptoms including hyperactivity, developmental delay, and intellectual disability. Because the detailed pathological mechanisms of most IEMs are unknown, there are no treatments for resulting neurological issues. Myoung-Hwan Kim at Seoul National University and co-workers investigated whether they could treat the neurological symptoms of the IEM, aminopeptidase P1 (APP1) deficiency. They found that APP1 deficiency in mice caused an increase in the neural receptor NMDAR. Suppressing NMDAR reduced both neurological and behavioral symptoms. These findings suggest potential treatments for APP1 deficiency, and indicate that neurodevelopmental disorders in IEMs may be treated by repairing the neural circuitry instead of the root metabolic cause.
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Affiliation(s)
- Young-Soo Bae
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Sang Ho Yoon
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, 03080, Korea
| | - Young Sook Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Sung Pyo Oh
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Woo Seok Song
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.,Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, 03080, Korea
| | - Jin Hee Cha
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Myoung-Hwan Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea. .,Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, 03080, Korea. .,Seoul National University Bundang Hospital, Seongnam, Gyeonggi, 13620, Korea.
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2
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Altered hippocampal gene expression, glial cell population, and neuronal excitability in aminopeptidase P1 deficiency. Sci Rep 2021; 11:932. [PMID: 33441619 PMCID: PMC7806765 DOI: 10.1038/s41598-020-79656-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/04/2020] [Indexed: 01/09/2023] Open
Abstract
Inborn errors of metabolism are often associated with neurodevelopmental disorders and brain injury. A deficiency of aminopeptidase P1, a proline-specific endopeptidase encoded by the Xpnpep1 gene, causes neurological complications in both humans and mice. In addition, aminopeptidase P1-deficient mice exhibit hippocampal neurodegeneration and impaired hippocampus-dependent learning and memory. However, the molecular and cellular changes associated with hippocampal pathology in aminopeptidase P1 deficiency are unclear. We show here that a deficiency of aminopeptidase P1 modifies the glial population and neuronal excitability in the hippocampus. Microarray and real-time quantitative reverse transcription-polymerase chain reaction analyses identified 14 differentially expressed genes (Casp1, Ccnd1, Myoc, Opalin, Aldh1a2, Aspa, Spp1, Gstm6, Serpinb1a, Pdlim1, Dsp, Tnfaip6, Slc6a20a, Slc22a2) in the Xpnpep1−/− hippocampus. In the hippocampus, aminopeptidase P1-expression signals were mainly detected in neurons. However, deficiency of aminopeptidase P1 resulted in fewer hippocampal astrocytes and increased density of microglia in the hippocampal CA3 area. In addition, Xpnpep1−/− CA3b pyramidal neurons were more excitable than wild-type neurons. These results indicate that insufficient astrocytic neuroprotection and enhanced neuronal excitability may underlie neurodegeneration and hippocampal dysfunction in aminopeptidase P1 deficiency.
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3
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Bae YS, Yoon SH, Han JY, Woo J, Cho YS, Kwon SK, Bae YC, Kim D, Kim E, Kim MH. Deficiency of aminopeptidase P1 causes behavioral hyperactivity, cognitive deficits, and hippocampal neurodegeneration. GENES BRAIN AND BEHAVIOR 2017; 17:126-138. [PMID: 28834604 DOI: 10.1111/gbb.12419] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/14/2017] [Accepted: 08/21/2017] [Indexed: 12/14/2022]
Abstract
Metabolic diseases affect various organs including the brain. Accumulation or depletion of substrates frequently leads to brain injury and dysfunction. Deficiency of aminopeptidase P1, a cytosolic proline-specific peptidase encoded by the Xpnpep1 gene, causes an inborn error of metabolism (IEM) characterized by peptiduria in humans. We previously reported that knockout of aminopeptidase P1 in mice causes neurodevelopmental disorders and peptiduria. However, little is known about the pathophysiological role of aminopeptidase P1 in the brain. Here, we show that loss of aminopeptidase P1 causes behavioral and neurological deficits in mice. Mice deficient in aminopeptidase P1 (Xpnpep1-/- ) display abnormally enhanced locomotor activities in both the home cage and open-field box. The aminopeptidase P1 deficiency in mice also resulted in severe impairments in novel-object recognition, the Morris water maze task, and contextual, but not cued, fear memory. These behavioral dysfunctions were accompanied by epileptiform electroencephalogram activity and neurodegeneration in the hippocampus. However, mice with a heterozygous mutation for aminopeptidase P1 (Xpnpep1+/- ) exhibited normal behaviors and brain structure. These results suggest that loss of aminopeptidase P1 leads to behavioral, cognitive and neurological deficits. This study may provide insight into new pathogenic mechanisms for brain dysfunction related to IEMs.
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Affiliation(s)
- Y-S Bae
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - S H Yoon
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - J Y Han
- Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Korea
| | - J Woo
- Department of Biological Sciences, KAIST, Daejeon, Korea
| | - Y S Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - S-K Kwon
- Department of Biological Sciences, KAIST, Daejeon, Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Y C Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - D Kim
- Department of Biological Sciences, KAIST, Daejeon, Korea
| | - E Kim
- Department of Biological Sciences, KAIST, Daejeon, Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - M-H Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea.,Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Korea.,Seoul National University Bundang Hospital, Seongnam, Gyeonggi, Korea
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4
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Iyer S, La-Borde PJ, Payne KAP, Parsons MR, Turner AJ, Isaac RE, Acharya KR. Crystal structure of X-prolyl aminopeptidase from Caenorhabditis elegans: A cytosolic enzyme with a di-nuclear active site. FEBS Open Bio 2015; 5:292-302. [PMID: 25905034 PMCID: PMC4404410 DOI: 10.1016/j.fob.2015.03.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/28/2015] [Accepted: 03/30/2015] [Indexed: 01/22/2023] Open
Abstract
Eukaryotic aminopeptidase P1 (APP1), also known as X‐prolyl aminopeptidase (XPNPEP1) in human tissues, is a cytosolic exopeptidase that preferentially removes amino acids from the N‐terminus of peptides possessing a penultimate N‐terminal proline residue. The enzyme has an important role in the catabolism of proline containing peptides since peptide bonds adjacent to the imino acid proline are resistant to cleavage by most peptidases. We show that recombinant and catalytically activeCaenorhabditis elegans APP‐1 is a dimer that uses dinuclear zinc at the active site and, for the first time, we provide structural information for a eukaryotic APP‐1 in complex with the inhibitor, apstatin. Our analysis reveals thatC. elegans APP‐1 shares similar mode of substrate binding and a common catalytic mechanism with other known X‐prolyl aminopeptidases. We present the crystal structure ofC. elegans APP‐1 both in bound and unbound forms. We showC. elegans APP‐1 uses dinuclear zinc at the active site. We confirm thatC. elegans APP‐1 is biological dimer. Our analysis reveals thatC. elegans APP‐1 shares a common catalytic mechanism with other X‐prolyl aminopeptidases.
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Key Words
- APP1, aminopeptidase P1
- Apstatin
- CCP4, computational collaborative project 4
- Di-nuclear active site
- ICP-AES, inductively coupled plasma atomic emission spectroscopy
- ICP-MS, inductively coupled plasma mass spectrometry
- MAP, methionine aminopeptidase
- NMR, nuclear magnetic resonance
- PCR, polymerase chain reaction
- PEG3350, polyethylene glycol 3350
- Protease inhibitor
- X-prolyl aminopeptidase
- X-ray crystallography
- XPNPEP, X-prolyl aminopeptidase
- Zinc metalloprotease
- rmsd, root mean square deviation
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Affiliation(s)
- Shalini Iyer
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Penelope J La-Borde
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK ; School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Karl A P Payne
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK ; Faculty of Life Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Mark R Parsons
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK ; Sevenoaks School, Sevenoaks TN13 1HU, UK
| | - Anthony J Turner
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
| | - R Elwyn Isaac
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
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5
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Yoon SH, Bae YS, Mun MS, Park KY, Ye SK, Kim E, Kim MH. Developmental retardation, microcephaly, and peptiduria in mice without aminopeptidase P1. Biochem Biophys Res Commun 2012; 429:204-9. [PMID: 23131567 DOI: 10.1016/j.bbrc.2012.10.104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 10/25/2012] [Indexed: 11/28/2022]
Abstract
Cytosolic aminopeptidase P1 (APP1) is one of the three known mammalian aminopeptidase Ps (APPs) that cleave the N-terminal amino acid residue of peptides in which the penultimate amino acid is proline. In mammals, many biologically active peptides have a highly conserved N-terminal penultimate proline. However, little is known about the physiological role of APP1. In addition, there is no direct evidence to associate a deficiency in APP1 with metabolic diseases. Although two human subjects with reduced APP activity exhibited peptiduria, it is unclear which of the three APP isoforms is responsible for this disorder. In this study, we generated APP1-deficient mice by knocking out Xpnpep1. Mouse APP1 deficiency causes severe growth retardation, microcephaly, and modest lethality. In addition, imino-oligopeptide excretion was observed in urine samples from APP1-deficient mice. These results suggest an essential role for APP1-mediated peptide metabolism in body and brain development, and indicate a strong causal link between APP1 deficiency and peptiduria.
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Affiliation(s)
- Sang Ho Yoon
- Department of Physiolgy, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
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6
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Molinaro G, Carmona A, Juliano M, Juliano L, Malitskaya E, Yessine MA, Chagnon M, Lepage Y, Simmons W, Boileau G, Adam A. Human recombinant membrane-bound aminopeptidase P: production of a soluble form and characterization using novel, internally quenched fluorescent substrates. Biochem J 2005; 385:389-97. [PMID: 15361070 PMCID: PMC1134709 DOI: 10.1042/bj20040849] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Revised: 08/09/2004] [Accepted: 09/13/2004] [Indexed: 11/17/2022]
Abstract
APP (aminopeptidase P) has the unique ability to cleave the N-terminal amino acid residue from peptides exhibiting a proline at P(1)'. Despite its putative involvement in the processing of bioactive peptides, among them the kinins, little is known about the physiological roles of both human forms of APP. The purpose of the present study is first to engineer and characterize a secreted form of hmAPP (human membrane-bound APP). Our biochemical analysis has shown that the expressed glycosylated protein is fully functional, and exhibits enzymic parameters similar to those described previously for mAPP purified from porcine or bovine lungs or expressed from a porcine clone. This soluble form of hmAPP cross-reacts with a polyclonal antiserum raised against a 469-amino-acid hmAPP fragment produced in Escherichia coli. Secondly, we synthesized three internally quenched fluorescent peptide substrates that exhibit a similar affinity for the enzyme than its natural substrates, the kinins, and a higher affinity compared with the tripeptide Arg-Pro-Pro used until now for the quantification of APP in biological samples. These new substrates represent a helpful analytical tool for rapid and reliable screening of patients susceptible to adverse reactions associated with angiotensin-converting enzyme inhibitors or novel vasopeptidase (mixed angiotensin-converting enzyme/neprilysin) inhibitors.
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Key Words
- adverse reaction
- aminopeptidase p
- glycosylphosphatidylinositol anchor
- internally quenched fluorescent substrate
- kinin
- screening test
- abz, o-aminobenzoic acid
- ace, angiotensin i-converting enzyme
- acei, ace inhibitor
- app, aminopeptidase p
- bk, bradykinin
- bk1–8, des-arg9-bk
- cpn, carboxypeptidase n
- dmem, dulbecco's modified eagle's medium
- dnp, 2,4-dinitrophenyl
- endo h, endoglycosidase h
- gpi, glycosylphosphatidylinositol
- hek-293 cells, human embryonic kidney 293 cells
- mapp, membrane-bound app
- hmapp, human mapp
- pngase f, peptide n-glycosidase f
- rpp, arg-pro-pro tripeptide
- secnep, soluble secreted neprilysin
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Affiliation(s)
- Giuseppe Molinaro
- *Faculté de Pharmacie, Université de Montréal, 2900, boul Édouard-Montpetit (bureau S338), C. P. 6128, succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Adriana K. Carmona
- †Department of Biophysics, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil
| | - Maria A. Juliano
- †Department of Biophysics, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil
| | - Luiz Juliano
- †Department of Biophysics, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil
| | - Elena Malitskaya
- ‡Département de biochimie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Marie-Andrée Yessine
- *Faculté de Pharmacie, Université de Montréal, 2900, boul Édouard-Montpetit (bureau S338), C. P. 6128, succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Miguel Chagnon
- §Faculté des Arts et des Sciences, Département de Mathématiques et de Statistique, Université de Montréal, Montréal, Québec, Canada
| | - Yves Lepage
- §Faculté des Arts et des Sciences, Département de Mathématiques et de Statistique, Université de Montréal, Montréal, Québec, Canada
| | - William H. Simmons
- ∥Division of Biochemistry, Department of Cell Biology, Neurobiology and Anatomy, Loyola University Chicago Stritch School of Medicine, Maywood, IL, U.S.A
| | - Guy Boileau
- ‡Département de biochimie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Albert Adam
- *Faculté de Pharmacie, Université de Montréal, 2900, boul Édouard-Montpetit (bureau S338), C. P. 6128, succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
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7
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Abstract
The cell surface has various functions: communicating with other cells, integrating into the tissue, and interacting with the extracellular matrix. Proteases play a key role in these processes. This review focuses on cell-surface peptidases (ectopeptidases, oligopeptidases) that are involved in the inactivation or activation of extracellular regulatory peptides, hormones, paracrine peptides, cytokines, and neuropeptides. The nomenclature of cell-surface peptidases is explained in relation to other proteases, and information is provided on membrane anchoring, catalytic sites, regulation, and, in particular, on their physiological and pharmacological importance. Furthermore, nonenzymatic (binding) functions and participation in intracellular signal transduction of cell surfaces peptidases are described. An overview on the different cell-surface peptidases is given, and their divergent functions are explained in detail. An example of actual pharmacological importance, dipeptidyl-peptidase IV (CD26), is discussed.
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Affiliation(s)
- Rolf Mentlein
- Department of Anatomy, University of Kiel, 24098 Kiel, Germany
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8
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Sprinkle TJ, Caldwell C, Ryan JW. Cloning, chromosomal sublocalization of the human soluble aminopeptidase P gene (XPNPEP1) to 10q25.3 and conservation of the putative proton shuttle and metal ligand binding sites with XPNPEP2. Arch Biochem Biophys 2000; 378:51-6. [PMID: 10871044 DOI: 10.1006/abbi.2000.1792] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human soluble ("cytosolic") aminopeptidase P (hsAmP) is an aminoacylprolyl hydrolase (EC 3.4.11.9) present in all tissues yet examined. hsAmP is related in terms of catalytic specificity to an ectoenzyme, membrane aminopeptidase P (hmAmP), which is largely limited in distribution to endothelia and brush border epithelia. Although both enzymes can degrade oligopeptides having N-terminal Xaa-Pro- moieties, hsAmP and hmAmP are of relatively low sequence homology. Recently, it has been shown that the two enzymes are not products of splice variants of the same gene. How hsAmP relates to hmAmP has clinical significance in that both can inactivate bradykinin, and AmP deficiency states have been described. The hmAmP gene (XPNPEP2) is disposed at chromosome Xq25, a disposition with clear meaning in terms of inheritance of hmAmP deficiencies. To further explore similarities and differences between hsAmP and hmAmP, the present study was begun to determine the chromosomal disposition of the hsAmP gene. Here we show that the gene is sublocalized on chromosome 10q25.3. We also show that hsAmP and hmAmP contain homologous blocks of sequence common to members of the "pita bread-fold" protein family, of which Escherichia coli methionine aminopeptidase is the prototype. The prototype is known to contain a proton shuttle and five divalent metal ligands, counterparts of which we identify in the homologous blocks of sequence in both hsAmP and hmAmP and compare to E. coli aminopeptidase.
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Affiliation(s)
- T J Sprinkle
- Department of Neurology, Medical College of Georgia and Veterans Administration Medical Center, Augusta 30912, USA.
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9
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Sprinkle TJ, Stone AA, Venema RC, Denslow ND, Caldwell C, Ryan JW. Assignment of the membrane-bound human aminopeptidase P gene (XPNPEP2) to chromosome Xq25. Genomics 1998; 50:114-6. [PMID: 9628831 DOI: 10.1006/geno.1998.5302] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- T J Sprinkle
- Department of Neurology, Medical College of Georgia, Augusta, Georgia 30912, USA.
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10
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Abstract
Proline is unique among the 20 amino acids due to its cyclic structure. This specific conformation imposes many restrictions on the structural aspects of peptides and proteins and confers particular biological properties upon a wide range of physiologically important biomolecules. In order to adequately deal with such peptides, nature has developed a group of enzymes that recognise this residue specifically. These peptidases cover practically all situations where a proline residue might occur in a potential substrate. In this paper we endeavour to discuss these enzymes, particularly those responsible for peptide or protein hydrolysis at proline sites. We have detailed their discovery, biochemical attributes and substrate specificities and have provided information as to the methodology used to detect and manipulate their activities. We have also described the roles, or potential roles that these enzymes may play physiologically and the consequences of their dysfunction in varied disease states.
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Affiliation(s)
- D F Cunningham
- School of Biological Sciences, Dublin City University, Dublin, Ireland
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11
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Reichelt KL, Teigland-Gjerstad B. Decreased urinary peptide excretion in schizophrenic patients after neuroleptic treatment. Psychiatry Res 1995; 58:171-6. [PMID: 8570770 DOI: 10.1016/0165-1781(95)02629-b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Six schizophrenic patients had their urinary peptide levels measured before and after 5 weeks of treatment with neuroleptic medications. For two patients, levels were also measured after a reduction in the neuroleptic dose. Because of the heterogeneity of peptide peaks with the same bioactivity, the overall peptide levels were compared to initial levels. A neuroleptic effect on peptide levels was demonstrated. Several research groups have reported enzyme induction caused by neuroleptics in vivo.
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Affiliation(s)
- K L Reichelt
- Department of Pediatric Research, University of Oslo, Rikshospitalet, Norway
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12
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Vanhoof G, De Meester I, van Sande M, Scharpé S, Yaron A. Distribution of proline-specific aminopeptidases in human tissues and body fluids. EUROPEAN JOURNAL OF CLINICAL CHEMISTRY AND CLINICAL BIOCHEMISTRY : JOURNAL OF THE FORUM OF EUROPEAN CLINICAL CHEMISTRY SOCIETIES 1992; 30:333-8. [PMID: 1380841 DOI: 10.1515/cclm.1992.30.6.333] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The proline-specific peptidases, aminopeptidase P (EC 3.4.11.9) and dipeptidyl peptidase IV (EC 3.4.14.5), were measured in human tissue homogenates and physiological fluids. All tissues examined contained measurable aminopeptidase P and dipeptidyl peptidase IV activities. High specific activities for both enzymes under study were found in benign prostatic hypertrophy. Normal prostate and prostatic adenocarcinoma had a much lower activity. This difference, however, is not reflected in the serum values of the patients. The most striking finding is the extremely high activity of dipeptidyl peptidase IV in prostatosomes, prostate-derived organelles, which occur freely in human seminal plasma, and which are important for enhancement of sperm forward motility.
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Affiliation(s)
- G Vanhoof
- Department of Medical Biochemistry, Faculty of Medicine, University of Antwerp, Wilrijk, Belgium
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13
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Hooper NM, Hryszko J, Oppong SY, Turner AJ. Inhibition by converting enzyme inhibitors of pig kidney aminopeptidase P. Hypertension 1992; 19:281-5. [PMID: 1312513 DOI: 10.1161/01.hyp.19.3.281] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Several inhibitors of angiotensin converting enzyme were also found to inhibit aminopeptidase P, whereas inhibitors of other mammalian aminopeptidases were ineffective. Aminopeptidase P purified from pig kidney cortex was found to contain one atom of zinc per polypeptide chain, confirming its metalloenzyme nature. The concentrations of converting enzyme inhibitors required to cause 50% inhibition (I50) of aminopeptidase P were in the low micromolar range. The most potent converting enzyme inhibitors toward aminopeptidase P were the carboxylalkyl compounds, cilazaprilat, enalaprilat, and ramiprilat (I50 values of 3-12 microM). The sulfhydryl compounds captopril (I50 110 microM) and YS980 (I50 20 microM) were slightly less potent at inhibiting aminopeptidase P. In contrast, the carboxylalkyl compounds benazeprilat, lisinopril, and pentoprilat; the sulfhydryl compound rentiapril; and the phosphoryl compounds ceranopril and fosinoprilat had no inhibitory effect against aminopeptidase P. This compares with I50 values in the 1-6 nM range for these inhibitors with angiotensin converting enzyme. Inhibition of aminopeptidase P may account for some of the effects or side effects noted with the clinical use of converting enzyme inhibitors. These results may provide the basis for the design of more selective inhibitors of angiotensin converting enzyme or mixed inhibitors of aminopeptidase P and angiotensin converting enzyme, or both.
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Affiliation(s)
- N M Hooper
- Department of Biochemistry and Molecular Biology, University of Leeds, UK
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14
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Harbeck HT, Mentlein R. Aminopeptidase P from rat brain. Purification and action on bioactive peptides. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 198:451-8. [PMID: 1645659 DOI: 10.1111/j.1432-1033.1991.tb16035.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Aminopeptidase P (EC 3.4.11.9) was purified from rat brain cytosol. A subunit Mr of 71,000 was determined for the reduced, denaturated protein whereas an Mr of 143,000 was determined for the native enzyme. The purified aminopeptidase P selectively liberated all unblocked, preferentially basic or hydrophobic ultimate amino acids from di-, tri- and oligopeptides with N-terminal Xaa-Pro- sequences. Corresponding peptides with penultimate Ala instead of Pro were cleaved with much lower rates; oligopeptides with residues other than Pro or Ala in the penultimate position appeared not to be substrates for the enzyme. Several bioactive peptides with Xaa-Pro sequences, especially bradykinin, substance P, corticortropin-like intermediate lobe peptide, casomorphin and [Tyr]melanostatin were shortened by the N-terminal amino acid by aminopeptidase P action. Rat brain aminopeptidase P was optimally active at pH 7.6-8.0 in the presence of Mn2+. Chelating agents and SH-reacting reagents inhibited the enzyme, but common inhibitors of aminopeptidases, like amastatin or bestatin, of prolidase or of dipeptidyl peptidases II and IV, like N-benzoyloxycarbonyl-proline or epsilon-benzyl-oxycarbonyl-lysyl-proline, as well as antibiotics like beta-lactam ones, bacitracin or puromycin, had little or no effect.
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Affiliation(s)
- H T Harbeck
- Anatomisches Institut der Universität Kiel, Federal Republic of Germany
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