Novel single-chain variant of antibody against mesothelin established by phage library.

Mesothelin (MSLN) shows increased expression in various cancer cells. For clinical application of antibodies as a positron emission tomography (PET) imaging reagent, a human shortened antibody is essential both for avoiding redundant immune responses and for providing rapid imaging. Therefore, we cloned a single-chain fragment of variable regions (scFv) from a human-derived gene sequence. This was achieved through the construction of a naïve phage library derived from human tonsil lymphocytes. Using a column with human recombinant MSLN, we carried out bio-panning of phage-variants by colony formation. We first obtained 120 clones that were subjected to selection in an ELISA using human recombinant MSLN as a solid phase antigen, and 15 phage clones of scFv with a different sequence were selected and investigated by flow cytometry (FCM). Then, six variants were selected and the individual scFv gene was synthesized in the VL and VH domains and expressed in Chinese hamster ovary cells. Mammalian cell-derived human-origin scFv clones were analyzed by FCM again, and one MSLN highly specific scFv clone was established. PET imaging by 89 Zr-labeled scFv was done in mice bearing xenografts with MSLN-expressing cancer cells, and tumor legions were successfully visualized. The scFv variant established in the present study may be potentially useful for cancer diagnosis by PET imaging.

The Function of ß2-glycoprotein I in Angiogenesis and Its in Vivo Distribution in Tumor Xenografts.

Intact ß2-glycoprotein I (iß2GPI) is a glycoprotein that regulates coagulation and fibrinolysis. Nicked ß2GPI (nß2GPI) possesses an angiogenic property at a relatively low concentration, and an antiangiogenic property at a high concentration. Here we investigated the functions of ßi 2GPI and nß2GPI in vascular endothelial growth factor (VEGF)-A-induced endothelial cell proliferation and tube formation. We used noninvasive PET imaging to analyze the ｉｎ　ｖｉｖｏ distribution of intravenously injected ß2GPI variants in tumor lesions in mice. iß2GPI was incubated with plasmin to obtain nß2GPI, and its N-terminal sequence was analyzed. nß2GPI had at least one other cleavage site upstream of the ß2GPI's domain V, whereas the former plasmin-cleavage site locates between K317 and T318. Both of intact and nicked ß2GPI significantly inhibited the VEGF-A-induced cell proliferation and the tube formation of human umbilical vein endothelial cells (HUVECs). PET imaging visualized considerably distributed intensities of all tested ß2GPI variants in tumor lesions of pancreatic tumor cell-xenografts. These results indicate that ß2GPI may be physiologically and pathophysiologically important in the regulation of not only coagulation and fibrinolysis, but also angiogenesis.

The conventional antihistamine drug cyproheptadine lacks QT-interval-prolonging action in halothane-anesthetized guinea pigs: comparison with hydroxyzine.

Antihistamines are known to belong to the chemical class that may induce long QT syndrome. Among them, cyproheptadine has been shown to exert multifaceted actions on the ventricular repolarization phase; namely, shortening of the action potential duration at supra-therapeutic concentrations of 2 - 8 µM and prolongation of the QT interval at ≥ 10 µM. Since information is limited regarding the in vivo electrophysiological effects of cyproheptadine, we assessed it using the halothane-anesthetized guinea-pig model, which was compared with effects of another antihistamine drug, hydroxyzine. Sub-therapeutic to therapeutic doses of hydroxyzine at 1 and 10 mg/kg, i.v. prolonged the QT interval and duration of monophasic action potential, whereas therapeutic to supra-therapeutic doses of cyproheptadine at 0.1 and 1 mg/kg, i.v. hardly affected the indices of ventricular repolarization. These results suggest that cyproheptadine may be categorized into antihistamines with little effect on the ventricular repolarization.

Ectopic calcification: importance of common nanoparticle scaffolds containing oxidized acidic lipids.

The term nanobacteria, sometimes referred to as nanobacteria-like particles (NLPs), is presently recognized as a misnomer for inert calcified nanoparticles. However, misinterpretation of its propagation as a living organism still continues. Ultrastructural and elemental analyses, combining immuno-electron microscopy with an original NLP isolate (P-17) derived from urinary stones, and an IgM monoclonal antibody (CL-15) raised against P-17 have now revealed that, oxidized lipids with acidified functional groups were key elements in NLP propagation. Lamellar structures composed of acidic/oxidized lipids provided structural scaffolds for carbonate apatite crystals. During in vitro culture, lipid peroxidation induced by γ-irradiation of FBS was a major cause of accelerated NLP propagation. In pathological tissue samples from hyperlipidemic atherosclerosis-prone mice, CL-15 co-localized with fatty plaques, macrophage infiltrates and osteocalcin staining of aortic valve lesions. These observations indicate that naturally occurring NLP composed of mineralo-oxidized lipids complexes are generated as by-products rather than etiological agents of chronic inflammation. FROM THE CLINICAL EDITOR: The term "nanobacteria-like particles (NLPs)" is presently recognized as a misnomer for inert calcified nanoparticles as opposed to living organisms. This study convincingly demonstrates that naturally occurring NLPs composed of mineralo-oxidized lipid complexes are generated as by-products rather than etiological agents of chronic inflammation.

Effects of the fluoroquinolone antibacterial drug ciprofloxacin on ventricular repolarization in the halothane-anesthetized Guinea pig.

The fluoroquinolone antibiotic ciprofloxacin has been reported to block delayed rectifier K(+) channels at much higher concentrations than those at which it exerts its bactericidal activity. In this study using the halothane-anesthetized guinea pig, we assessed whether ciprofloxacin has a proarrhythmic activity. Ciprofloxacin at a clinically relevant dose of 3 mg/kg, i.v. did not affect any electrocardiographic parameters. At 10 mg/kg, it prolonged the QT interval and the duration of the monophasic action potential of the ventricle under sinus rhythm and constant ventricular pacing (n = 6). The extents of its effects on the ventricular repolarization phase were comparable to those of another fluoroquinolone antibiotic moxifloxacin at a clinically relevant dose of 3 mg/kg (n = 6). Meanwhile, the PR interval and QRS width were also increased by ciprofloxacin at 10 mg/kg, suggesting that the drug inhibited cardiac K(+) channels as well as Na(+) and Ca(2+) channels in vivo. These results suggest that ciprofloxacin exerted a multi-ion channel-blocking action in the heart within the supra-therapeutic dose range. Therefore, careful observation may be necessary for patients with heart disease receiving a higher dose of ciprofloxacin in order to prevent the emergence of resistance.

Novel Self-Forming Nanosized DDS Particles for BNCT: Utilizing A Hydrophobic Boron Cluster and Its Molecular Glue Effect.

BNCT is a non-invasive cancer therapy that allows for cancer cell death without harming adjacent cells. However, the application is limited, owing to the challenges of working with clinically approved boron (B) compounds and drug delivery systems (DDS). To address the issues, we developed self-forming nanoparticles consisting of a biodegradable polymer, namely, "AB-type Lactosome (AB-Lac)" loaded with B compounds. Three carborane isomers (o-, m-, and p-carborane) and three related alkylated derivatives, i.e., 1,2-dimethy-o-carborane (diC1-Carb), 1,2-dihexyl-o-carborane (diC6-Carb), and 1,2-didodecyl-o-carborane (diC12-Carb), were separately loaded. diC6-Carb was highly loaded with AB-Lac particles, and their stability indicated the "molecular glue" effect. The efficiency of in vitro B uptake of diC6-Carb for BNCT was confirmed at non-cytotoxic concentration in several cancer cell lines. In vivo/ex vivo biodistribution studies indicated that the AB-Lac particles were remarkably accumulated within 72 h post-injection in the tumor lesions of mice bearing syngeneic breast cancer (4T1) cells, but the maximum accumulation was reached at 12 h. In ex vivo B biodistribution, the ratios of tumor/normal tissue (T/N) and tumor/blood (T/Bl) of the diC6-Carb-loaded particles remained stably high up to 72 h. Therefore, we propose the diC6-Carb-loaded AB-Lac particles as a promising candidate medicine for BNCT.

Nicked {beta}2-glycoprotein I binds angiostatin 4.5 (plasminogen kringle 1-5) and attenuates its antiangiogenic property.

Angiostatin was first discovered as a plasminogen fragment with antitumor/antiangiogenic property. One of the angiostatin isoforms, that is, angiostatin 4.5 (AS4.5), consisting of plasminogen kringle 1 to 4 and a most part of kringle 5, is produced by autoproteolysis and present in human plasma. beta2-glycoprotein I (beta2GPI) is proteolytically cleaved by plasmin in its domain V (nicked beta2GPI), resulting in binding to plasminogen. Antiangiogenic properties have been recently reported in nicked beta2GPI as well as in intact beta2GPI at higher concentrations. In the present study, we found significant binding of nicked beta2GPI to AS4.5 (K(D) = 3.27 x 10(6) M(-1)). Via this binding, nicked beta2GPI attenuates the antiangiogenic functions of AS4.5 in the proliferation of arterial/venous endothelial cells, in the extracellular matrix invasion and the tube formation of venous endothelial cells, and in vivo angiogenesis. In contrast, intact beta2GPI does not bind to AS4.5 or inhibit its antiangiogenic activity. Thus, nicked beta2GPI exerts dual effects on angiogenesis, that is, nicked beta2GPI promotes angiogenesis in the presence of AS4.5, whereas nicked beta2GPI inhibits angiogenesis at concentrations high enough to neutralize AS4.5. Our data suggest that plasmin-nicked beta2GPI promotes angiogenesis by interacting with plasmin-generated AS4.5 in sites of increased fibrinolysis such as thrombus.

In vivo oxidation, platelet activation and simultaneous occurrence of natural immunity in atherosclerosis-prone mice.

BACKGROUND: Several murine models are susceptible to atherosclerosis, such as low density-lipoprotein receptor-deficient (LDLR-/-) and apolipoprotein E-deficient (apoE-/-) mice, and are used for studying pathophysiological mechanisms. Atherosclerotic lesions in the aortic valve and thoracic/abdominal aorta are commonly associated with hyperlipidemia. We recently demonstrated the development of large atherosclerotic plaques in Helicobacter pylori-infected heterozygous LDLR+/- apoE+/- mice. OBJECTIVES: To measure novel biomarkers related to atherosclerosis, blood coagulation, and oxidative stress in order to investigate their possible pathogenic roles in atherosclerosis-prone mice. METHODS: Mice were fed with a normal chow diet or high-fat diet and sacrificed at different age intervals to measure aortic plaque size. Plasma cholesterol was enzymatically measured. Enzyme-linked immunosorbent assay was used to measure oxidized LDL (oxLDL)/beta-2-glycoprotein I (beta2GPI) complexes, immunoglobulin M (IgM) antibodies against native LDL, oxLDL, or oxLDL/beta2GPI, and urine 11-dehydro-thromboxane B2 (11-dhTxB2) or 8-hydroxy-deoxyguanosine. RESULTS: There was a parallel increase in plaque size, plasma cholesterol, and urinary 11-dhTxB2 in atherosclerosis-prone mice. In contrast to atherosclerosis-prone strains, an elevation of urinary 11-dhTxB2 with no significant plaque generation was observed in LDLR+/- 1 apoE+/- mice. The atherogenic autoantigen oxLDL/beta2GPI complex was detected only in LDLRI mice. These levels seem to depend on plaque size. IgM antibodies against oxLDL in apoE-/- mice were found, accompanied by atherosclerotic progression. CONCLUSIONS: Progression of atherosclerotic lesions was associated not only with hypercholesterolemia but also with platelet activation and natural autoimmune-mediated regulatory mechanism(s) in murine models.

Lactosome-Conjugated siRNA Nanoparticles for Photo-Enhanced Gene Silencing in Cancer Cells.

The A3B-type Lactosome comprised of poly(sarcosine)3-block-poly(l-lactic acid), a biocompatible and biodegradable polymeric nanomicelle, was reported to accumulate in tumors in vivo via the enhanced permeability and retention (EPR) effect. Recently, the cellular uptake of Lactosome particles was enhanced through the incorporation of a cell-penetrating peptide (CPP), L7EB1. However, the ability of Lactosome as a drug delivery carrier has not been established. Herein, we have developed a method to conjugate the A3B-type Lactosome with ATP-binding cassette transporter G2 (ABCG2) siRNA for inducing in vitro apoptosis in the cancer cell lines PANC-1 and NCI-H226. The L7EB1 peptide facilitates the cellular uptake efficiency of Lactosome but does not deliver siRNA into cytosol. To establish the photoinduced cytosolic dispersion of siRNA, a photosensitizer loaded L7EB1-Lactosome was prepared, and the photosensitizer 5,10,15,20-tetra-kis(pentafluorophenyl)porphyrin (TPFPP) showed superiority in photoinduced cytosolic dispersion. We exploited the combined effects of enhanced cellular uptake by L7EB1 and photoinduced endosomal escape by TPFPP to efficiently deliver ABCG2 siRNA into the cytosol for gene silencing. Moreover, the silencing of ABCG2, a protoporphyrin IX (PpIX) transporter, also mediated photoinduced cell death via 5-aminolevulinic acid (ALA)-mediated PpIX accumulated photodynamic therapy (PDT). The synergistic capability of the L7EB1/TPFPP/siRNA-Lactosome complex enabled both gene silencing and PDT.

A Novel 89Zr-labeled DDS Device Utilizing Human IgG Variant (scFv): "Lactosome" Nanoparticle-Based Theranostics for PET Imaging and Targeted Therapy.

"Theranostics," a new concept of medical advances featuring a fusion of therapeutic and diagnostic systems, provides promising prospects in personalized medicine, especially cancer. The theranostics system comprises a novel 89Zr-labeled drug delivery system (DDS), derived from the novel biodegradable polymeric micelle, "Lactosome" nanoparticles conjugated with specific shortened IgG variant, and aims to successfully deliver therapeutically effective molecules, such as the apoptosis-inducing small interfering RNA (siRNA) intracellularly while offering simultaneous tumor visualization via PET imaging. A 27 kDa-human single chain variable fragment (scFv) of IgG to establish clinically applicable PET imaging and theranostics in cancer medicine was fabricated to target mesothelin (MSLN), a 40 kDa-differentiation-related cell surface glycoprotein antigen, which is frequently and highly expressed by malignant tumors. This system coupled with the cell penetrating peptide (CPP)-modified and photosensitizer (e.g., 5, 10, 15, 20-tetrakis (4-aminophenyl) porphyrin (TPP))-loaded Lactosome particles for photochemical internalized (PCI) driven intracellular siRNA delivery and the combination of 5-aminolevulinic acid (ALA) photodynamic therapy (PDT) offers a promising nano-theranostic-based cancer therapy via its targeted apoptosis-inducing feature. This review focuses on the combined advances in nanotechnology and material sciences utilizing the "89Zr-labeled CPP and TPP-loaded Lactosome particles" and future directions based on important milestones and recent developments in this platform.

Antioxidative attributes of rice bran extracts in ameliorative effects of atherosclerosis-associated risk factors.

Oxidative stress, chronic inflammation, dyslipidemia, hyperglycemia, and shear stress (physical effect) are risk factors associated with the pathogenesis of atherosclerosis. Rice bran, a by-product of rice milling process, is known to house polyphenols and vitamins which exhibit potent antioxidant and anti-inflammatory properties. Through recent emerging knowledge of rice bran in health and wellness, the present study was aimed to assess the ameliorative effects of rice bran extracts (RBE) derived from Japanese colored rice varieties in modulating risk factors of atherosclerosis via in vitro and in vivo study models. Pre-treatment of lipopolysaccharide (LPS)-stimulated murine J774A.1 macrophage-like cells with RBE alleviated nitric oxide (NO) overproduction and downregulated gene expressions of pro-inflammatory modulators: tumor necrosis factor-α (TNF-α), interleukin (IL)-α (IL-1α), IL-1ß, IL-6, and inducible nitric oxide synthase (iNOS). In addition, RBE also significantly attenuated LPS-stimulated protein expressions of iNOS, TNF-α, IL-1α, and IL-6 in J774A.1 macrophage-like cells as compared to non-treated LPS control group. In in vivo, 12 weeks of RBE dietary supplementations significantly reduced (p < 0.05) total cholesterol, triglycerides, and pro-atherogenic oxidized LDL/ß2-glycoprotein I (oxLDL/ß2GPI) complexes at plasma levels, in high fat diet (HFD) induced low density lipoprotein receptor knockout (Ldlr -/-) mice. En face pathological assessments of murine aortas also revealed significant reductions by 38% (p < 0.05) in plaque sizes of RBE-supplemented HFD mice groups as compared to non RBE-supplemented HFD control mice group. Moreover, gene expressions of aortic (iNOS, TNF-α, IL-1ß) and hepatic (TNF-α, IL-1α, IL-1ß) pro-inflammatory modulators were also downregulated in RBE-supplemented mice groups. Present study has revealed the potent health attributes and application of RBE as a dietary supplement to attenuate risks of inadvertent oxidative damage and chronic inflammation underlying the pathogenesis of atherosclerosis. Intrinsically, present preliminary findings may provide global health prospects for future dietary implementation of RBE in management of atherosclerosis.

Autoimmunity, infectious immunity, and atherosclerosis.

INTRODUCTION: Vascular inflammation is common in certain systemic autoimmune diseases and contributes to the oxidation of low-density lipoprotein (oxLDL) and oxLDL/beta2-glycoprotein I (beta2GPI) complex formation. These complexes have been implicated as proatherogenic autoantigens that participate in the development of atherosclerotic disease. DISCUSSION: We have demonstrated that the in vitro macrophage uptake of oxLDL/beta2GPI complexes increases in the presence of IgG anti-beta2GPI antibodies and that IgG immune complexes containing oxLDL/beta2GPI upregulate the expression of both scavenger and Fcgamma receptors to activate beta2GPI specific T cells. Some persistent infections may cause immune responses that promote atherogenesis. Cellular immunity (Th1) against Helicobacter pylori (H. pylori) derived heat shock protein 60 (Hp-HSP60) cross-reacts with endogenous HSP60 to cause cardiovascular disease likely by molecular mimicry. CONCLUSION: Infectious cellular response may be proatherogenic,while the humoral response (antibody production) maybe protective. We review the recent progress in our understanding of autoimmunity and infectious immunity that promote atherosclerosis.

Synthesis of new camptothecin analogs with improved antitumor activities.

Novel hexacyclic camptothecin analogs containing cyclic amidine, urea, or thiourea moiety were designed and synthesized based on the proposed 3D-structure of the topoisomerase I (Topo I)/DNA/camptothecin ternary complex. The analogs were prepared from 9-nitrocamptothecin via 7,9-diaminocamptothecin derivatives as a key intermediate. Among them, 7c exhibited in vivo antitumor activities superior to CPT-11 in human cancer xenograft models in mice at their maximum tolerated doses though its in vitro antiproliferative activity was comparable to SN-38 against corresponding cell lines.

Synthesis and biological activities of a pH-dependently activated water-soluble prodrug of a novel hexacyclic camptothecin analog.

CH0793076 (1) is a novel hexacyclic camptothecin analog showing potent antitumor activity in various human caner xenograft models. To improve the water solubility of 1, water-soluble prodrugs were designed to generate an active drug 1 nonenzymatically, thus expected to show less interpatient PK variability than CPT-11. Among the prodrugs synthesized, 4c (TP300, hydrochloride) having a glycylsarcosyl ester at the C-20 position of 1 is highly water-soluble (>10mg/ml), stable below pH 4 and rapidly generates 1 at physiological pH in vitro. The rapid (ca. <1min) generation of 1 after incubation of TP300 with plasma (mouse, rat, dog and monkey) was also demonstrated. TP300 showed a broader antitumor spectrum and more potent antitumor activity than CPT-11 in various human cancer xenograft models.

Atherosclerosis in autoimmune diseases.

Lipid peroxidation occurs frequently in patients with systemic autoimmune diseases and contributes to autoimmune vascular inflammation. Oxidized low-density lipoprotein (oxLDL) interacts with beta2-glycoprotein I (beta2GPI), forming oxLDL/beta2GPI complexes. Circulating oxLDL/beta2GPI complexes and autoantibodies to these complexes have been demonstrated in patients with systemic lupus erythematosus and antiphospholipid syndrome. These findings suggest an immunogenic nature of the complexes and an active proatherogenic role in autoimmunity. Biochemical characterization of the complexes and immunohistochemical studies of atherosclerotic lesions suggest that most of the complexes originate in the arterial wall and are released into circulation. The in vitro macrophage uptake of oxLDL/beta2GPI complexes increased significantly in the presence of antiphospholipid antibodies (anti-beta2GPI), suggesting that macrophage Fcgamma receptors are involved in the lipid intracellular influx that leads to foam cell formation. These findings provide an immunologic explanation for the accelerated development of atherosclerosis seen in systemic lupus erythematosus and antiphospholipid syndrome.

Preventing autoimmune and infection triggered atherosclerosis for an enduring healthful lifestyle.

Atherosclerosis is a chronic inflammatory disease of the arteries associated with various risk factors that promote lipid abnormalities (i.e., dyslipidemia), development and progression of atherosclerotic lesions, plaque rupture, and vascular thrombosis. Experimental evidence from biochemical and clinical studies support the idea that arterial thrombosis is an autoimmune process resulting from 'autoantibody'-mediated pro-atherogenic mechanisms now seen in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). In addition, it has been shown that persistent infections of Chlamydia pneumoniae (C. pneumoniae), Porphyromonas gingivalis (P. gingivalis), and Helicobacter pylori (H. pylori) cause immune responses (infectious immunity) in their hosts that promote atherogenesis. In this article, we review recent progress in our understanding of immune- and infection-mediated atherosclerosis.

Oxidative modification of low-density lipoprotein and immune regulation of atherosclerosis.

Oxidized low-density lipoprotein (oxLDL) is thought to promote atherosclerosis through complex inflammatory and immunologic mechanisms that lead to lipid dysregulation and foam cell formation. Recent findings suggested that oxLDL forms complexes with beta2-glycoprotein I (beta2GPI) and/or C-reactive protein (CRP) in the intima of atherosclerotic lesions. Autoantibodies against oxLDL/beta2GPI complexes occur in patients with systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS) and significantly correlate with arterial thrombosis. IgG autoantibodies having similar specificity emerged spontaneously in non-immunized NZWxBXSB F1 mice, an animal model of APS, and a monoclonal autoantibody (WB-CAL-1; IgG2a) against complexed beta2GPI (oxLDL/beta2GPI complexes) was derived from the same mice. WB-CAL-1 significantly increased the in vitro uptake of oxLDL/beta(2)GPI complexes by macrophages. This observation strongly suggests that such IgG autoantibodies are pro-atherogenic. In contrast, IgM anti-oxLDL natural antibodies found in the atherosclerosis-prone mice (ApoE(-/-) and LDL-R(-/-) mice) have been proposed to be anti-atherogenic (protective). The presence of IgG anti-oxLDL antibodies in humans has been documented in many publications but their exact clinical significance remains unclear. In this article, we review recent progress in our understanding of the mechanisms involved in oxidation of LDL, formation of oxLDL complexes, and antibody mediated-immune regulation of atherogenesis.

Radiologist supply and workload: international comparison--Working Group of Japanese College of Radiology.

PURPOSE: The aim of this study was to compare radiology statistics and procedures across the world with an eye to lightening the workload of radiologists in Japan. METHODS: Literature and data in the public domain were obtained for Organization for Economic Cooperation and Development (OECD) member countries. This study collected and analyzed the number of (diagnostic) radiologists and physicians, computed tomography/magnetic resonance (CT/MR) units, CT/MR examinations, and workload of radiologists. RESULTS: Data for the number of radiologists and CT/MR units were obtained from 26 countries and, among them, data for the number of CT/MR examinations for 17 countries. The study found that in 2004 Japan had only 36 radiologists per million population, which is one-third the national average of the 26 countries surveyed, making Japan one of the lowest ranked countries. The workload of a radiologist (CT/MR examinations/year) in Japan was calculated at 6130. This is 4.3 times the global average (1440 for the 17 countries). CONCLUSIONS: This comparison showed that the number of radiologists in Japan is the lowest among the 26 countries, and the workload is the highest. The study also showed that for Japan to provide sustainable and quality health care 8614 diagnostic radiologists--2.5 times the present number- -would be required.

Corrigendum to "Cytoprotective and Cytotoxic Effects of Rice Bran Extracts in Rat H9c2(2-1) Cardiomyocytes".

[This corrects the article DOI: 10.1155/2016/6943053.].

Mutants of ß2-glycoprotein I: Their features and potent applications.

ß2-Glycoprotein I (ß2GPI) is a highly-glycosylated plasma protein composed of five homologous domains which regulates coagulation, fibrinolysis, and/or angiogenesis by interacting to negatively charged hydrophobic molecules and/or with plasminogen and its metabolites. The present study focused on structural and functional characterization of ß2GPI's domain I (DI) and V (DV). Through N-terminal amino acid sequencing, a novel plasmin-cleaved site at K287C288 was identified in DV. We further modified the intact DV by altering two amino acids at specific proteolytic cleavage sites to generate three stable DV mutants: DV(PP), (PE), and (AA). Results of both SDS-PAGE and MALDI-TOF-MS showed that all three DV mutants were more stable than the intact DV, and DV(PE) was predominantly resistant to proteolysis. Competitive ELISA assessed affinities of intact ß2GPI and those mutants to cardiolipin. In culture system, all DV and DI mutants potently inhibited HUVEC's proliferation by 18-30% as compared to control. Only DI and nicked ß2GPI showed significant inhibition in HUVEC's tube formation. Moreover, DV(PE)-coated affinity columns demonstrated its binding property towards anionic lipids and could substantially isolate anionic DOPS from zwitterionic DOPC as a purification model. In summary, the proteolytic resistant and unhindered phospholipid (PL) binding properties of DV(PE) have made it an appealing element for subsequent prospective studies. Future in-depth characterization and optimized applications of cleavage-resistant DV(PE) would complement its full capacity as a novel clinical modality in the field of vascular imaging and/or lipidomics studies.