共查询到20条相似文献,搜索用时 37 毫秒
1.
Yuji O. Kamatari Yosuke Hayano Kei‐ichi Yamaguchi Junji Hosokawa‐Muto Kazuo Kuwata 《Protein science : a publication of the Protein Society》2013,22(1):22-34
A variety of antiprion compounds have been reported that are effective in ex vivo and in vivo treatment experiments. However, the molecular mechanisms for most of these compounds remain unknown. Here we classified antiprion mechanisms into four categories: I, specific conformational stabilization; II, nonspecific stabilization; III, aggregation; and IV, interaction with molecules other than PrPC. To characterize antiprion compounds based on this classification, we determined their binding affinities to PrPC using surface plasmon resonance and their binding sites on PrPC using NMR spectroscopy. GN8 and GJP49 bound specifically to the hot spot in PrPC, and acted as “medical chaperones” to stabilize the native conformation. Thus, mechanisms I was predominant. In contrast, quinacrine and epigallocathechin bound to PrPC rather nonspecifically; these may stabilize the PrPC conformation nonspecifically including the interference with the intermolecular interaction following mechanism II. Congo red and pentosan polysulfate bound to PrPC and caused aggregation and precipitation of PrPC, thus reducing the effective concentration of prion protein. Thus, mechanism III was appropriate. Finally, CP‐60, an edarabone derivative, did not bind to PrPC. Thus these were classified into mechanism IV. However, their antiprion activities were not confirmed in the GT + FK system, whose details remain to be elucidated. This proposed antiprion mechanisms of diverse antiprion compounds could help to elucidate their antiprion activities and facilitate effective antiprion drug discovery. 相似文献
2.
《Biophysical journal》2022,121(14):2813-2825
Misfolding of the cellular prion protein (PrPC) is associated with lethal neurodegeneration. PrPC consists of a flexible tail (residues 23–123) and a globular domain (residues 124–231) whose C-terminal end is anchored to the cell membrane. The neurotoxic antibody POM1 and the innocuous antibody POM6 recognize the globular domain. Experimental evidence indicates that POM1 binding to PrPC emulates the influence on PrPC of the misfolded prion protein (PrPSc) while the binding of POM6 has the opposite biological response. Little is known about the potential interactions between flexible tail, globular domain, and the membrane. Here, we used atomistic simulations to investigate how these interactions are modulated by the binding of the Fab fragments of POM1 and POM6 to PrPC and by interstitial sequence truncations to the flexible tail. The simulations show that the binding of the antibodies restricts the range of orientations of the globular domain with respect to the membrane and decreases the distance between tail and membrane. Five of the six sequence truncations influence only marginally this distance and the contact patterns between tail and globular domain. The only exception is a truncation coupled to a charge inversion mutation of four N-terminal residues, which increases the distance of the flexible tail from the membrane. The interactions of the flexible tail and globular domain are modulated differently by the two antibodies. 相似文献
3.
DLP1‐dependent mitochondrial fragmentation and redistribution mediate prion‐associated mitochondrial dysfunction and neuronal death
下载免费PDF全文
![点击此处可从《Aging cell》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chaosi Li Di Wang Wei Wu Wei Yang Syed Zahid Ali Shah Ying Zhao Yuhan Duan Lu Wang Xiangmei Zhou Deming Zhao Lifeng Yang 《Aging cell》2018,17(1)
Mitochondrial malfunction is a universal and critical step in the pathogenesis of many neurodegenerative diseases including prion diseases. Dynamin‐like protein 1 (DLP1) is one of the key regulators of mitochondrial fission. In this study, we investigated the role of DLP1 in mitochondrial fragmentation and dysfunction in neurons using in vitro and in vivo prion disease models. Mitochondria became fragmented and redistributed from axons to soma, correlated with increased mitochondrial DLP1 expression in murine primary neurons (N2a cells) treated with the prion peptide PrP106–126 in vitro as well as in prion strain‐infected hamster brain in vivo. Suppression of DLP1 expression by DPL1 RNAi inhibited prion‐induced mitochondrial fragmentation and dysfunction (measured by ADP/ATP ratio, mitochondrial membrane potential, and mitochondrial integrity). We also demonstrated that DLP1 RNAi is neuroprotective against prion peptide in N2a cells as shown by improved cell viability and decreased apoptosis markers, caspase 3 induced by PrP106–126. On the contrary, overexpression of DLP1 exacerbated mitochondrial dysfunction and cell death. Moreover, inhibition of DLP1 expression ameliorated PrP106–126‐induced neurite loss and synaptic abnormalities (i.e., loss of dendritic spine and PSD‐95, a postsynaptic scaffolding protein as a marker of synaptic plasticity) in primary neurons, suggesting that altered DLP1 expression and mitochondrial fragmentation are upstream events that mediate PrP106–126‐induced neuron loss and degeneration. Our findings suggest that DLP1‐dependent mitochondrial fragmentation and redistribution plays a pivotal role in PrPSc‐associated mitochondria dysfunction and neuron apoptosis. Inhibition of DLP1 may be a novel and effective strategy in the prevention and treatment of prion diseases. 相似文献
4.
Nathalie Daude Agnes Lau Ilaria Vanni Sang-Gyun Kang Andrew R. Castle Serene Wohlgemuth Lyudmyla Dorosh Holger Wille Maria Stepanova David Westaway 《The Journal of biological chemistry》2022,298(4)
The cellular prion protein (PrPC) has a C-terminal globular domain and a disordered N-terminal region encompassing five octarepeats (ORs). Encounters between Cu(II) ions and four OR sites produce interchangeable binding geometries; however, the significance of Cu(II) binding to ORs in different combinations is unclear. To understand the impact of specific binding geometries, OR variants were designed that interact with multiple or single Cu(II) ions in specific locked coordinations. Unexpectedly, we found that one mutant produced detergent-insoluble, protease-resistant species in cells in the absence of exposure to the infectious prion protein isoform, scrapie-associated prion protein (PrPSc). Formation of these assemblies, visible as puncta, was reversible and dependent upon medium formulation. Cobalamin (Cbl), a dietary cofactor containing a corrin ring that coordinates a Co3+ ion, was identified as a key medium component, and its effect was validated by reconstitution experiments. Although we failed to find evidence that Cbl interacts with Cu-binding OR regions, we instead noted interactions of Cbl with the PrPC C-terminal domain. We found that some interactions occurred at a binding site of planar tetrapyrrole compounds on the isolated globular domain, but others did not, and N-terminal sequences additionally had a marked effect on their presence and position. Our studies define a conditional effect of Cbl wherein a mutant OR region can act in cis to destabilize a globular domain with a wild type sequence. The unexpected intersection between the properties of PrPSc''s disordered region, Cbl, and conformational remodeling events may have implications for understanding sporadic prion disease that does not involve exposure to PrPSc. 相似文献
5.
Pravas K. Baral Jiang Yin Adriano Aguzzi Michael N. G. James 《Protein science : a publication of the Protein Society》2019,28(12):2055-2063
Prion diseases in mammals are caused by a conformational transition of the cellular prion protein from its native conformation (PrPC) to a pathological isoform called “prion protein scrapie” (PrPSc). A molecular level of understanding of this conformational transition will be helpful in unveiling the disease etiology. Experimental structural biological techniques (NMR and X‐ray crystallography) have been used to unravel the atomic level structural information for the prion and its binding partners. More than one hundred three‐dimensional structures of the mammalian prions have been deposited in the protein databank. Structural studies on the prion protein and its structural transitions will deepen our understanding of the molecular basis of prion pathogenesis and will provide valuable guidance for future structure‐based drug discovery endeavors. 相似文献
6.
Olivier Julien Subhrangsu Chatterjee Angela Thiessen Steffen P. Graether Brian D. Sykes 《Protein science : a publication of the Protein Society》2009,18(10):2172-2182
Prion diseases, or transmissible spongiform encephalopathies, are a group of infectious neurological diseases associated with the structural conversion of an endogenous protein (PrP) in the central nervous system. There are two major forms of this protein: the native and noninfectious cellular form, PrPC; and the misfolded, infectious, and proteinase K‐resistant form, PrPSc. The C‐terminal domain of PrPC is mainly α‐helical in structure, whereas PrPSc in known to aggregate into an assembly of β‐sheets, forming amyloid fibrils. To identify the regions of PrPC potentially involved in the initial steps of the conversion to the infectious conformation, we have used high‐resolution NMR spectroscopy to characterize the stability and structure of bovine recombinant PrPC (residues 121 to 230) during unfolding with the denaturant urea. Analysis of the 800 MHz 1H NMR spectra reveals region‐specific information about the structural changes occurring upon unfolding. Our data suggest that the dissociation of the native β‐sheet of PrPC is a primary step in the urea‐induced unfolding process, while strong hydrophobic interactions between helices α1 and α3, and between α2 and α3, stabilize these regions even at very high concentrations of urea. 相似文献
7.
Magdalini Polymenidou Rita Moos Mike Scott Christina Sigurdson Yong-zhong Shi Bill Yajima Iva Hafner-Bratkovi? Roman Jerala Simone Hornemann Kurt Wuthrich Anne Bellon Martin Vey Graciela Garen Michael N. G. James Nat Kav Adriano Aguzzi 《PloS one》2008,3(12)
PrPSc, a misfolded and aggregated form of the cellular prion protein PrPC, is the only defined constituent of the transmissible agent causing prion diseases. Expression of PrPC in the host organism is necessary for prion replication and for prion neurotoxicity. Understanding prion diseases necessitates detailed structural insights into PrPC and PrPSc. Towards this goal, we have developed a comprehensive collection of monoclonal antibodies denoted POM1 to POM19 and directed against many different epitopes of mouse PrPC. Three epitopes are located within the N-terminal octarepeat region, one is situated within the central unstructured region, and four epitopes are discontinuous within the globular C-proximal domain of PrPC. Some of these antibodies recognize epitopes that are resilient to protease digestion in PrPSc. Other antibodies immunoprecipitate PrPC, but not PrPSc. A third group was found to immunoprecipitate both PrP isoforms. Some of the latter antibodies could be blocked with epitope-mimicking peptides, and incubation with an excess of these peptides allowed for immunochromatography of PrPC and PrPSc. Amino-proximal antibodies were found to react with repetitive PrPC epitopes, thereby vastly increasing their avidity. We have also created functional single-chain miniantibodies from selected POMs, which retained the binding characteristics despite their low molecular mass. The POM collection, thus, represents a unique set of reagents allowing for studies with a variety of techniques, including western blotting, ELISA, immunoprecipitation, conformation-dependent immunoassays, and plasmon surface plasmon resonance-based assays. 相似文献
8.
Conversion of native cellular prion protein (PrPc) from an α-helical structure to a toxic and infectious β-sheet structure (PrPSc) is a critical step in the development of prion disease. There are some indications that the formation of PrPSc is preceded by a β-sheet rich PrP (PrPβ) form which is non-infectious, but is an intermediate in the formation of infectious PrPSc. Furthermore the presence of lipid cofactors is thought to be critical in the formation of both intermediate-PrPβ and lethal, infectious PrPSc. We previously discovered that the endotoxin, lipopolysaccharide (LPS), interacts with recombinant PrPc and induces rapid conformational change to a β-sheet rich structure. This LPS induced PrPβ structure exhibits PrPSc-like features including proteinase K (PK) resistance and the capacity to form large oligomers and rod-like fibrils. LPS is a large, complex molecule with lipid, polysaccharide, 2-keto-3-deoxyoctonate (Kdo) and glucosamine components. To learn more about which LPS chemical constituents are critical for binding PrPc and inducing β-sheet conversion we systematically investigated which chemical components of LPS either bind or induce PrP conversion to PrPβ. We analyzed this PrP conversion using resolution enhanced native acidic gel electrophoresis (RENAGE), tryptophan fluorescence, circular dichroism, electron microscopy and PK resistance. Our results indicate that a minimal version of LPS (called detoxified and partially de-acylated LPS or dLPS) containing a portion of the polysaccharide and a portion of the lipid component is sufficient for PrP conversion. Lipid components, alone, and saccharide components, alone, are insufficient for conversion. 相似文献
9.
10.
Takashi Onodera Akikazu Sakudo Hirokazu Tsubone Shigeyoshi Itohara 《Microbiology and immunology》2014,58(7):361-374
Deletion of cellular isoform of prion protein (PrPC) increases neuronal predisposition to damage by modulating apoptosis and the negative consequences of oxidative stress. In vivo studies have demonstrated that PrPC‐deficient mice are more prone to seizure, depression, and induction of epilepsy and experience extensive cerebral damage following ischemic challenge or viral infection. In addition, adenovirus‐mediated overexpression of PrPC reduces brain damage in rat models of cerebral ischemia. In experimental autoimmune encephalomyelitis, PrPC‐deficient mice reportedly have a more aggressive disease onset and less clinical improvement during the chronic phase than wild‐type mice mice. In mice given oral dextran sulfate, PrPC has a potential protective role against inflammatory bowel disease. PrPC‐deficient mice demonstrate significantly greater increases in blood glucose concentrations after intraperitoneal injection of glucose than wild‐type mice. Further in vivo challenges to PrP gene‐deficient models and conditional knockout models with siRNA and in vivo administration of PrP‐ligating agents may assist in refining knowledge of the lymphoid function of PrPC and predicting the effects of anti‐PrP treatment on the immune system. Together, these findings indicate that PrPC may have multiple neuroprotective and anti‐inflammatory roles, which explains why this protein is so widely expressed. 相似文献
11.
Stephan Schwarzinger Anselm H. C. Horn Jan Ziegler Heinrich Sticht 《Journal of biomolecular structure & dynamics》2013,31(6):581-590
Abstract The prion protein is thought to induce prion diseases by changing its conformation from the cellular form, PrPc, into the infectious Scrapie-form, PrPSc. Little is known about the structural and dynamical features of this conformational change. We here introduce a novel concept that involves rare large scale motions between the subdomains βl-αl-β2 and α2-α3 in the carboxy-terminal, globular part of PrP. The interface between these two subdomains carries most pathogenic mutations known to be associated with prion diseases. Based on computational simulations as well as experimental results we propose that such a large scale motion subsequently destabilizes large parts of the cellular conformer PrPc, thus, rendering it prone to structural rearrangements, including aggregation of now partially unfolded parts of the PrP sequence. We hypothesize that such large scale motions occur as a rare event even under equilibrium conditions and that the interaction of such partially destabilized PrPc-conformers, which we named PrPc*, contributes to the formation of pathogenic oligomeric species of the prion protein. 相似文献
12.
13.
Noriyuki Nishida Shigeru Katamine Kazuto Shigematsu Akira Nakatani Nobuhiro Sakamoto Sumitaka Hasegawa Ryota Nakaoke Ryuichiro Atarashi Yasufumi Kataoka Tsutomu Miyamoto 《Cellular and molecular neurobiology》1997,17(5):537-545
1. The cellular prion protein, designated PrPc, is a key molecule in the prion diseases but its physiological function remains unknown. To elucidate whether PrPc plays some role in the central nervous system, we established a line of mice in which the PrP gene had been disrupted and subsequently conducted long-term observations.2. Performance in latent learning and passive avoidance was evaluated using water-finding and step-through tests, respectively.3. PrP
–/– mice showed impaired performance in the water-finding test, indicating a disturbance in latent learning, at 23 weeks of age. In the step-through test, although the PrP
–/– mice showed normal learning ability and short-term memory retention, they evidenced a significant disturbance in long-term memory retention.4. These results indicate that PrPc is needed for certain types of learning and memory and that the loss of function of this protein may contribute to the pathogenesis of prion diseases. 相似文献
14.
《Biochimica et Biophysica Acta - Proteins and Proteomics》2018,1866(9):982-988
Prion (PrP) diseases are neurodegenerative diseases characterized by the formation of β-sheet rich, insoluble and protease resistant protein deposits (called PrPSc) that occur throughout the brain. Formation of synthetic or in vitro PrPSc can occur through on-pathway toxic oligomers. Similarly, toxic and infectious oligomers identified in cell and animal models of prion disease indicate that soluble oligomers are likely intermediates in the formation of insoluble PrPSc. Despite the critical role of prion oligomers in disease progression, little is known about their structure. In order, to obtain structural insight into prion oligomers, we generated oligomers by shaking-induced conversion of recombinant, monomeric prion protein PrPc (spanning residues 90–231). We then obtained two-dimensional solution NMR spectra of the PrPc monomer, a 40% converted oligomer, and a 94% converted oligomer. Heteronuclear single-quantum correlation (1H–15N) studies revealed that, in comparison to monomeric PrPc, the oligomer has intense amide peak signals in the N-terminal (residues 90–114) and C-terminal regions (residues 226–231). Furthermore, a core region with decreased mobility is revealed from residues ~127 to 225. Within this core oligomer region with decreased mobility, there is a pocket of increased amide peak signal corresponding to the middle of α-helix 2 and the loop between α-helices 2 and 3 in the PrPc monomer structure. Using high-resolution solution-state NMR, this work reveals detailed and divergent residue-specific changes in soluble oligomeric models of PrP. 相似文献
15.
Christopher J Silva 《朊病毒》2014,8(1):42-50
Prions are molecular pathogens, able to convert a normal cellular prion protein (PrPC) into a prion (PrPSc). The information necessary for this conversion is contained in the conformation of PrPSc. Mass spectrometry (MS) and small-molecule covalent reactions have been used to study prions. Mass spectrometry has been used to detect and quantitate prions in the attomole range (10?18 mole). MS-based analysis showed that both possess identical amino acid sequences, one disulfide bond, a GPI anchor, asparagine-linked sugar antennae, and unoxidized methionines. Mass spectrometry has been used to define elements of the secondary and tertiary structure of wild-type PrPSc and GPI-anchorless PrPSc. It has also been used to study the quaternary structure of the PrPSc multimer. Small molecule reagents react differently with the same lysine in the PrPC conformation than in the PrPSc conformation. Such differences can be detected by Western blot using mAbs with lysine-containing epitopes, such as 3F4 and 6D11. This permits the detection of PrPSc without the need for proteinase K pretreatment and can be used to distinguish among prion strains. These results illustrate how two important chemical tools, mass spectrometry and covalent modification by small molecules, are being applied to the detection and structural study of prions. Furthermore these tools are or can be applied to the study of the other protein misfolding diseases such as Alzheimer Disease, Parkinson Disease, or ALS. 相似文献
16.
Laura Botto Diana Cunati Silvia Coco Silvia Sesana Alessandra Bulbarelli Emiliano Biasini Laura Colombo Alessandro Negro Roberto Chiesa Massimo Masserini Paola Palestini 《PloS one》2014,9(5)
The prion protein (PrPC) is highly expressed within the nervous system. Similar to other GPI-anchored proteins, PrPC is found in lipid rafts, membrane domains enriched in cholesterol and sphingolipids. PrPC raft association, together with raft lipid composition, appears essential for the conversion of PrPC into the scrapie isoform PrPSc, and the development of prion disease. Controversial findings were reported on the nature of PrPC-containing rafts, as well as on the distribution of PrPC between rafts and non-raft membranes. We investigated PrPC/ganglioside relationships and their influence on PrPC localization in a neuronal cellular model, cerebellar granule cells. Our findings argue that in these cells at least two PrPC conformations coexist: in lipid rafts PrPC is present in the native folding (α-helical), stabilized by chemico-physical condition, while it is mainly present in other membrane compartments in a PrPSc-like conformation. We verified, by means of antibody reactivity and circular dichroism spectroscopy, that changes in lipid raft-ganglioside content alters PrPC conformation and interaction with lipid bilayers, without modifying PrPC distribution or cleavage. Our data provide new insights into the cellular mechanism of prion conversion and suggest that GM1-prion protein interaction at the cell surface could play a significant role in the mechanism predisposing to pathology. 相似文献
17.
Yuko Ushiki‐Kaku Yoshifumi Iwamaru Kentaro Masujin Morikazu Imamura Shigeyoshi Itohara Kiyoko Ogawa‐Goto Shunji Hattori Takashi Yokoyama 《Microbiology and immunology》2013,57(11):792-796
Limited information is available about conformational differences between the abnormal isoform of prion protein (PrPSc) and cellular prion protein (PrPC) under native conditions. To clarify conformational differences between these two isoforms, PrP‐deficient mice were immunized with brain homogenates of normal and scrapie‐infected animals. All mice generated anti‐PrP antibodies. Peptide array analysis of these serum samples revealed a distinctive epitope of PrPSc consisting of QGSPGGN (PrP41–47) at the N‐terminus. This study demonstrated a conformational dissimilarity at the N‐terminus between PrPSc and PrPC, a finding that may provide novel information about conformational features of PrPSc. 相似文献
18.
Deciphering the pathophysiologic events in prion diseases is challenging, and the role of posttranslational modifications (PTMs) such as glypidation and glycosylation remains elusive due to the lack of homogeneous protein preparations. So far, experimental studies have been limited in directly analyzing the earliest events of the conformational change of cellular prion protein (PrPC) into scrapie prion protein (PrPSc) that further propagates PrPC misfolding and aggregation at the cellular membrane, the initial site of prion infection, and PrP misfolding, by a lack of suitably modified PrP variants. PTMs of PrP, especially attachment of the glycosylphosphatidylinositol (GPI) anchor, have been shown to be crucially involved in the PrPSc formation. To this end, semisynthesis offers a unique possibility to understand PrP behavior invitro and invivo as it provides access to defined site‐selectively modified PrP variants. This approach relies on the production and chemoselective linkage of peptide segments, amenable to chemical modifications, with recombinantly produced protein segments. In this article, advances in understanding PrP conversion using semisynthesis as a tool to obtain homogeneous posttranslationally modified PrP will be discussed. 相似文献
19.
An insight into the thermodynamic characteristics of human thrombopoietin complexation with TN1 antibody
下载免费PDF全文
![点击此处可从《Protein science : a publication of the Protein Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Shigeki Arai Chie Shibazaki Motoyasu Adachi Eijiro Honjo Taro Tamada Yoshitake Maeda Tomoyuki Tahara Takashi Kato Hiroshi Miyazaki Michael Blaber Ryota Kuroki 《Protein science : a publication of the Protein Society》2016,25(10):1786-1796
Human thrombopoietin (hTPO) primarily stimulates megakaryocytopoiesis and platelet production and is neutralized by the mouse TN1 antibody. The thermodynamic characteristics of TN1 antibody–hTPO complexation were analyzed by isothermal titration calorimetry (ITC) using an antigen‐binding fragment (Fab) derived from the TN1 antibody (TN1‐Fab). To clarify the mechanism by which hTPO is recognized by TN1‐Fab the conformation of free TN1‐Fab was determined to a resolution of 2.0 Å using X‐ray crystallography and compared with the hTPO‐bound form of TN1‐Fab determined by a previous study. This structural comparison revealed that the conformation of TN1‐Fab does not substantially change after hTPO binding and a set of 15 water molecules is released from the antigen‐binding site (paratope) of TN1‐Fab upon hTPO complexation. Interestingly, the heat capacity change (ΔCp) measured by ITC (?1.52 ± 0.05 kJ mol?1 K?1) differed significantly from calculations based upon the X‐ray structure data of the hTPO‐bound and unbound forms of TN1‐Fab (?1.02 ~ 0.25 kJ mol?1 K?1) suggesting that hTPO undergoes an induced‐fit conformational change combined with significant desolvation upon TN1‐Fab binding. The results shed light on the structural biology associated with neutralizing antibody recognition. 相似文献
20.
Kaimann T Metzger S Kuhlmann K Brandt B Birkmann E Höltje HD Riesner D 《Journal of molecular biology》2008,376(2):582-596
Prions are the agents of a series of lethal neurodegenerative diseases. They are composed largely, if not entirely, of the host-encoded prion protein (PrP), which can exist in the cellular isoform PrPC and the pathological isoform PrPSc. The conformational change of the α-helical PrPC into β-sheet-rich PrPSc is the fundamental event of prion disease. The transition of recombinant PrP from a PrPC-like into a PrPSc-like conformation can be induced in vitro by submicellar concentrations of SDS. An α-helical dimer was identified that might represent either the native state of PrPC or the first step from the monomeric PrPC to highly aggregated PrPSc. In the present study, the molecular structure of these dimers was analyzed by introducing covalent cross-links using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. Inter- and intramolecular bonds between directly neighboured amino groups and carboxy groups were generated. The bonds formed in PrP dimers of recombinant PrP (90-231) were identified by tryptic digestion and subsequent mass spectrometric analysis. Intra- and intermolecular cross-links between N-terminal glycine and three acidic amino acid side chains in the globular part of PrP were identified, showing the N-terminal amino acids (90-124) are not as flexible as known from NMR analysis. When the cross-linked sites were used as structural constraint, molecular modeling calculations yielded a structural model for PrP dimer and its monomeric subunit, including the folding of amino acids 90-124 in addition to the known structure. Molecular dynamics of the structure after release of the constraint indicated an intrinsic stability of the domain of amino acids 90-124. 相似文献