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PubMed2002

[Sequence analysis of the fusion (F) protein genes of four Newcastle disease virus strains causing clinical disease in geese].

Four strains of Newcastle disease virus(NDV), which have proven to be responsible for the disease outbreaks in south and east China regions called "geese paramyxovirus infection" or "avian paramyxovirus infection of geese", were examined for the features of their fusion(F) protein genes. A 1700 nucleotides(nt) fragment of the F gene (1705 nt) of each of the 4 strains were sequenced, the results revealed that the NDV strains of goose origin share common transcriptional sequence and translational start position with the hitherto reported NDV, the F gene homologies among the 4 strains were 97.8%-98.9%, while the corresponding homologies between these strains and the standard challenge strain F48E8 were only 86.0-86.8%. The deduced amino acid sequences near cleavage site of F0 proteins showed a 112RRQKR/F117 motif, comforming well with that of the virulent strains. The cleavage sites distribution of 3 restriction enzymes(Hinf I, Basto I, Rsa I) in 75% region of the F gene(between 334-1682 nt), which is used to group NDV strains into different genotypes, were also analysed with the aid of computer program MegAlign, it is very interesting to find that the 4 strains showed a distinct distribution pattern from all the genotypes so far reported(genotype I-VIII), characterized by the simultaneously presence of a Bsto I site at 752 nt and two Rsa I sites at 872 nt and 973 nt. Additionally, 3 out of the 4 strains, despite their different geographical locations, showed a novel Rsa I site at position 1249 which is absent in all of the other genotypes. The 4 NDV strains of goose origin were essentially virulent ones, and probably belong to a new genotype.

Amino Acid Sequence↗
PubMed2004

Granulocyte-macrophage colony-stimulating factor and interleukin-2 fusion cDNA for cancer gene immunotherapy.

Genetic engineering of tumor cells to express both granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-2 can induce synergistic immune antitumor effects. Paradoxically, the combination has also been reported to down-regulate certain immune functions, highlighting the unpredictability of dual cytokine use. We hypothesized that a GM-CSF and IL-2 fusion transgene (GIFT) could circumvent such limitations yet preserve synergistic features. We designed a fusion cDNA of murine GM-CSF and IL-2. Protein structure computer modeling of GIFT protein predicted for intact ligand binding domains for both cytokines. B16 mouse melanoma cells were gene modified to express GIFT (B16GIFT), and these cells were unable to form tumors in C57bl/6 mice. Irradiated B16GIFT whole-cell tumor vaccine could also induce absolute protective immunity against challenge by live B16 cells. In mice with established melanoma, B16GIFT therapeutic cellular vaccine significantly improved tumor-free survival when compared with B16 expressing both IL-2 and GM-CSF. We show that GIFT induced a significantly greater tumor site recruitment of macrophages than combined GM-CSF and IL-2 and that macrophage recruitment arises from novel chemotactic feature of GIFT. In contrast to suppression by GM-CSF of natural killer (NK) cell recruitment despite coexpression of IL-2, GIFT leads to significant functional NK cell infiltration as confirmed in NK-defective beige mice. In conclusion, we demonstrated that a fusion between GM-CSF and IL-2 can invoke greater antitumor effect than both cytokines in combination, and novel immunobiological properties can arise from such chimeric constructs.

Amino Acid Sequence↗
PubMed1989

Trypanosoma cruzi: involvement of proteolytic activity during cell fusion induced by epimastigote form.

Human erythrocytes were fused by Trypanosoma cruzi from 7 and 14 day old culture (stationary and declination phases, respectively) while only lysis was induced by 4 day old culture parasite (exponential phase). Lysis and erythrocyte fusion were studied by phase contrast microscopy, measuring of hemolysis and gel electrophoresis. The fusogenicity is Ca2+-dependent while lysis is delayed in the absence of exogenous Ca2+. The proteolysis of erythrocyte protein bands 1, 2, 2.1, 2.3 and 3 are common features of both fusion and lysis processes. Nevertheless the breakdown rate of ankyrin (band 2.1) and band 3 are different in fused or in lysed cells. The lysis process is associated with a faster degradation of band 2.1 and increase of band 2.3 than in the case of the fusion process. By contrast, degradation of band 3 occurs faster in the fusion than in the lytic event. Treatment of fusogenic parasites but not erythrocytes with TPCK, soybean trypsin inhibitor or FCS inhibited to some extent the fusion process and the decrease of bands 1, 2, 2.1, 2.3 and 3. The results suggest that proteases from fusogenic parasites may be directly or indirectly involved in the proteolysis of band 2.1 in a way related to induction of fusion.

Animals↗
PubMed1990

Features of regenerated clones with or without fusion treatment between auxotrophic mutants of Streptomyces antibioticus and their antibiotic productivity.

During experiments on protoplast fusion of complementary auxotrophic mutants (194 and 11M-21) of Streptomyces antibioticus for strain improvement, the clones (typified by F-40) regenerated on minimal regeneration medium (MRM) were found to be prototrophs, and to produce an antibiotic different from those produced by the parent strain. The protoplast regeneration of each parent was examined as a negative control experiment. In the regenerated clones of 194, half of them produced actinomycins similar to those produced by the original mutant 194, but others (typified by R-20) seemed to produce antibiotics similar to those produced by F-40. In the taxonomic characterization of morphological, cultural, and physiological properties of each strain, F-40, R-20, and the parent mutant 194 had no significant differences with a few exceptions. The problem here is whether the antibiotic of R-20 is the same as that of F-40, which was first isolated and found to be a peptide antibiotic different from actinomycins, with activity against Gram-negative and Gram-positive bacteria.

Anti-Bacterial Agents↗
PubMed2003

A soluble peripherin/Rds C-terminal polypeptide promotes membrane fusion and changes conformation upon membrane association.

Photoreceptor rod cells contain a unique tetraspanin fusion protein known as peripherin/rds. This protein is important in membrane fusion events hypothesized to be essential to disk membrane morphogenesis and disk shedding. In vivo and in vitro fusogenic activity has been mapped to the C-terminal domain of peripherin/rds. Moreover, a fusion peptide domain localized to a 15 amino acid long region (residues 311-325) is essential for mediating lipid bilayer fusion of model membranes. To address the functional and structural properties required for peripherin/rds dependent membrane fusion, constructs of the entire C-terminal domain (residues 284-346) were generated and polypeptides expressed. A wild type-peripherin/rds C-terminal GST fusion construct that included the entire C-terminus (PERCTER) or a C-terminal truncation mutant (PERCTN) were engineered with a thrombin cleavage site. Protein expression was induced in E. coli with IPTG, expressed proteins cleaved from the GST with thrombin and purified to homogeneity on a Superdex 75 column. Purity was confirmed by SDS-PAGE and Western blot analysis. The purified wt C-terminal protein resolved as a monomer under reducing conditions on SDS-PAGE (15%) and was immunoreactive with anti peripherin/rds antibody 2B6 (gift from Dr R. Molday). The purified polypeptide promoted the requisite steps of fusion, membrane destabilization, lipid mixing and aqueous contents mixing. Conversely, the truncation mutant lacking a portion of the fusion domain was unable to promote these steps. A common feature of most membrane fusion proteins is a change in conformation upon membrane association. Structural changes in the C-terminal polypeptide were investigated using far UV CD. The far UV CD spectra of the purified C-terminal polypeptide indicated substantial alpha-helical content in the wt peptide in isotonic aqueous buffer. An increase in intensity of 208 and 222 nm CD bands upon addition of DPC vesicles indicated an increase in alpha-helical content of the polypeptide. These results demonstrate that a purified soluble form of the C-terminus of peripherin/rds can interact with biological phospholipids; moreover, this interaction promotes a conformational change that is most consistent with an increase in alpha-helical content.

Blotting, Western↗
PubMed2004

A capsid protein of nonenveloped Bluetongue virus exhibits membrane fusion activity.

The outer capsid layer of Bluetongue virus, a member of the nonenveloped Reoviridae family, is composed of two proteins, a receptor-binding protein, VP2, and a second protein, VP5, which shares structural features with class I fusion proteins of enveloped viruses. In the replication cycle of Bluetongue virus VP5 acts as a membrane permeabilization protein that mediates release of viral particles from endosomal compartments into the cytoplasm. Here, we show that VP5 can also act as a fusion protein and induce syncytium formation when it is fused to a transmembrane anchor and expressed on the cell surface. Fusion activity is strictly pH-dependent and is triggered by short exposure to low pH. No cell-cell fusion is observed at neutral pH. Deletion of the first 40 amino acids, which can fold into two amphipathic helices, abolishes fusion activity. Syncytium formation by VP5 is inhibited in the presence of VP2 when it is expressed in a membrane-anchored form. The data indicate an interaction between the outer capsid protein VP2 and VP5 and show that VP5 undergoes pH-dependent conformational changes that render it capable of interacting with cellular membranes. More importantly, our data show that a membrane permeabilization protein of a nonenveloped virus can evolve into a fusion protein by the addition of an appropriate transmembrane anchor. The results strongly suggest that the mechanism of membrane permeabilization by VP5 and membrane fusion by viral fusion proteins require similar structural features and conformational changes.

Amino Acid Motifs↗
PubMed1993

Reconstitution of a plasma-membrane H(+)-ATPase into bilayer lipid membrane.

The plasma membrane H(+)-ATPase of Neurospora has been reconstituted into planar lipid bilayer membranes by means of the vesicle-fusion technique described by Finkelstein and his collaborators (Zimmerberg et al., 1980; Cohen et al., 1980, 1984; Akabas et al., 1984). Enzyme was first transferred from isolated plasma membrane fragments into asolectin vesicles by a detergent-dialysis procedure (Perlin et al., 1984). After H(+)-pumping activity had been checked by quenching of acridine orange fluorescence, the vesicles were fused into performed bilayers. Critical features of the fusion process include (i) attachment of the vesicles to the bilayer in the presence of divalent cations (Mg++), and (ii) rapid osmotic swelling, which was enhanced by prior sonication or freeze-thawing of the vesicles, and/or by inclusions of physiologic channels. Enough proton pumps could be thus incorporated into bilayers to achieve ATP-driven, vanadate-sensitive currents of 0.04-0.4 pA. Aqueous solutions of low ionic strength were used to suppress conductance fluctuations due to the channels, and when that precaution was taken, we could demonstrate the proton pump the work against membrane potentials of at least 50 mV.

Acridine Orange↗
PubMed1980

Calcium-activated thiol-proteinase activity in the fusion of rat erythrocytes induced by benzyl alcohol.

1. Rat erythrocytes were fused by incubation with benzyl alcohol and Ca2+. 2. Cell fusion was inhibited by EGTA, N-ethylmaleimide, tetrathionate, iodoacetamide, cystamine, Tos-Lys-CH2Cl, and to a lesser extent by Tos-Phe-CH2Cl. Phenylmethanesulphonyl fluoride, Tos-Arg-OMe and histamine did not inhibit cell fusion. 3. Gel electrophoresis of membrane proteins from "ghosts" of the erythrocytes treated with benzyl alcohol showed that a high-molecular-weight polymer was present: this was consistent with the entry into the cells of Ca2+ and the activation of a transglutaminase enzyme. 4. In the treated cells the proteins corresponding to bands 2 and 3 in human erythrocytes were decreased, and a polypeptide with a slightly greater mobility than band 3 was produced. 5. These changes were inhibited by EGTA, N-ethylmaleimide, tetrathionate, iodoacetamide, cystamine, and Tos-Lys-CH2Cl, but not by phenylmethanesulphonyl fluoride, Tos-Arg-OMe, or histamine. 6. The intramembraneous particles of the P-fracture face of cells treated with benzyl alcohol to induce fusion were decreased in number and were susceptible to cold-induced aggregation; both of these phenomena were markedly inhibited to EGTA, and partially inhibited by Tos-Lys-CH2Cl and N-ethylmaleimide. 7. These several observations indicate that a Ca2+-activated thiol-proteinase, which acts to degrade membrane proteins and to give freedom of lateral movement to intramembranous particles, may be essential feature of membrane fusion in this system. 8. It is suggested that this proteinase may act to degrade spectrin-binding proteins that attach band-3 protein to the erythrocyte cytoskeleton.

Animals↗
PubMed1993

Observations on structural features and characteristics of biological apatite crystals. 8. Observation on fusion of human enamel crystals.

In a series of studies to investigate the basic structural features and characteristics of the biological apatite crystals, using a transmission electron microscope, we examined the ultrastructure of the human enamel, dentin, and bone crystals at near atomic resolution and showed the configuration of the hydroxyapatite structure through the cross and longitudinal sections of the crystals. Subsequently, based on the results of the observations by the authors of the ultrastructure of the tooth and bone, using the same approach, we have been able to directly examine the images of the lattice imperfections in the human tooth and bone crystals, such as the point defect structure, line defect, and face defect, in the crystals. In this report, we describe the images of the crystal fusion obtained by using the same approach from the sections of the human enamel crystals. The materials used for this study were the noncarious enamel from the freshly extracted human erupted lower first molars. The small cubes of the material were fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin using the routine methods. The ultrathin sections were cut with a diamond knife without decalcification. The sections were examined with the HITACHI H-800 H and H-9000 type transmission electron microscopes operated at 200 kV and 300 kV. Each crystal was observed at an initial magnification of 300,000 times and at a final magnification of 10,000,000 times and over. We are, therefore, able to confirm that the fusion between the adjacent crystals can occur at some time during the life history of the human enamel. We sincerely believe that the electron micrographs shown in this report are the first to show the ultrastructures of the crystal fusion in the human enamel crystals at near atomic resolution.

Crystallography↗
PubMed1988

Lambda ZAP: a bacteriophage lambda expression vector with in vivo excision properties.

A lambda insertion type cDNA cloning vector, Lambda ZAP, has been constructed. In E. coli a phagemid, pBluescript SK(-), contained within the vector, can be excised by f1 or M13 helper phage. The excision process eliminates the need to subclone DNA inserts from the lambda phage into a plasmid by restriction digestion and ligation. This is possible because Lambda ZAP incorporates the signals for both initiation and termination of DNA synthesis from the f1 bacteriophage origin of replication (1). Six of 21 restriction sites in the excised pBluescript SK polylinker, contained within the NH2-portion of the lacZ gene, are unique in lambda ZAP. Coding sequences inserted into these restriction sites, in the appropriate reading frame, can be expressed from the lacZ promoter as fusion proteins. The features of this vector significantly increase the rate at which clones can be isolated and analyzed. The lambda ZAP vector was tested by the preparation of a chicken liver cDNA library and the isolation of actin clones by screening with oligonucleotide probes. Putative actin clones were excised from the lambda vector and identified by DNA sequencing. The ability of lambda ZAP to serve as a vector for the construction of cDNA expression libraries was determined by detecting fusion proteins from clones containing glucocerbrosidase cDNA's using rabbit IgG anti-glucocerbrosidase antibodies.

Actins↗
PubMed2003

Biochemical and biophysical analysis of heptad repeat regions from the fusion protein of Menangle virus, a newly emergent paramyxovirus.

Menangle virus is a novel paramyxovirus isolated in Australia in 1997, but its classification position has not yet been finally settled. Here by using a computational program, LearnCoil-VMF, we determined the heptad repeat (HR) regions (HR1 and HR2) of Menangle virus F protein. Subsequently the HR1 and HR2 peptides were expressed as a single chain (named 2-Helix) connected by a six amino-acid linker as a GST fusion protein with an E. coli in vitro expression system. The GST-removed purified 2-Helix protein could form a stable trimer in vitro judging by gel-filtration and chemical cross-linking. CD spectra showed that the 2-Helix protein had a high percentage of alpha-helix and was very thermo-stable. Crystals of the 2-Helix protein preparations have been obtained in many conditions with hanging-drop diffusion method. These results indicated that Menangle virus has the common features of the fusion protein for other paramyxoviruses and should adopt a similar fusion mechanism to other members. As the HR regions of Menangle virus F protein could form stable six-helix bundle coiled coil structure, they should be used as drug target for the design of fusion inhibitors, as successfully used for other parmyxoviruses. This is especially relevant to such a newly emergent virus with zoonotic potentials.

Amino Acid Sequence↗
PubMed1995

Expression of a voltage-dependent potassium current precedes fusion of human muscle satellite cells (myoblasts).

Using the whole-cell recording patch clamp technique in clonal cultures of human muscle satellite cells (SC), we studied a voltage-gated potassium current analogous to the delayed rectifier current (IKdr) described in adult human skeletal muscle. This current was absent in proliferating SC cultured in a growth medium containing 15% serum, except when the SC approached the end of their replicative life (between 77 and 124 days in culture); at that time, approximately 50% of the SC possessed IKdr. In contrast, IKdr was expressed within less than 4 days in approximately 70% of the SC cultured in a serum-free medium (SFM) and within 24 h in differentiating medium. We believe that IKdr may be a characteristic feature of fusion-component SC and that it may be involved in the fusion process for the following reasons: 1) after the transfer in differentiating medium, cultures of SC in which the expression of IKdr was previously promoted by exposure to SFM were found to fuse immediately, without the initial 24 h lag time observed in control sister cultures; 2) in the latter "naive" SC, IKdr was expressed during the first day in differentiating medium, before SC began to fuse; 3) most of the SC that did not fuse even after weeks of exposure to differentiating medium did not express IKdr; 4) TEA, at a concentration of 3 mM, reduces the amplitude of IKdr by 55% and the fusion index by 55-67%.

Adolescent↗
PubMedDate not supplied

The use of the carbon-fiber reinforced modular implant for the reconstruction of the anterior column of the spine. A clinical and experimental study conducted on 42 cases.

The conservative treatment of neoplasms of the locomotor apparatus means the production of bone defects that may be filled with prostheses, bone grafts, systems of osteosynthesis. In the vertebral column, reconstruction of the resected elements--in the case of total vertebrectomy--requires the combination of anterior and posterior implants. It is the purpose of this study to analyze a group of 42 patients who, after accurate and uniform oncological (Enneking) and surgical (Weinstein-Boriani-Biagini) staging, were submitted to excision of one or more vertebral bodies for the treatment of neoplastic pathology, with reconstruction by prosthetic carbon fiber modular implant in order to obtain immediate stability, and to stimulate solid intervertebral fusion by bone grafts introduced inside the prosthesis. Thirty of the 42 patients presented with primary malignant tumor, 3 with benign tumor, 6 with solitary metastases, and 3 with plasmacytoma. In 32 cases, en bloc resection of the vertebral body was carried out (vertebrectomy) with combined anterior and posterior access in 29 patients (69.0%), and by posterior approach alone in 3 cases (7.1%). Ten intralesional corporectomies were carried out, 8 by anterior approach, 2 by posterior approach. The carbon prosthesis was filled with cortical and cancellous bone grafts in 38 cases. At a mean clinical and instrumental follow-up obtained 26 months after surgery for all of the patients, the use of a carbon prosthesis did not cause short- or long-term mechanical complications. The results of our study tend to affirm that the use of a carbon fiber modular implant may fill any loss of bone substance of the vertebral column, that it allows for immediate weight-bearing, and that if favors bone fusion. Some particular features of the carbon prosthesis favorably adapt to the surgical method of vertebrectomy: 1. The various components of the prosthesis may adapt to any type of bone resection of the vertebral body, even in unexpected situations; 2. Connection to posterior instrumentation in total vertebrectomies avoids the use of an anterior plate, thus reducing the time required for reconstruction of the anterior column, eliminating necessary surgical procedures in the segmental vascular structures. Finally, the radiolucency of the prosthesis allows for an easy evaluation of the formation of bone within and around the implant up to definitive anterior fusion and, of no less importance, early diagnosis of any local recurrence.

Adolescent↗
PubMed2002

Highly stable trimers formed by human immunodeficiency virus type 1 envelope glycoproteins fused with the trimeric motif of T4 bacteriophage fibritin.

The envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) function as a trimer composed of three gp120 exterior glycoproteins and three gp41 transmembrane proteins. Soluble gp140 glycoproteins composed of the uncleaved ectodomains of gp120 and gp41 form unstable, heterogeneous oligomers, but soluble gp140 trimers can be stabilized by fusion with a C-terminal, trimeric GCN4 motif (X. Yang et al., J. Virol. 74:5716-5725, 2000). To understand the influence of the C-terminal trimerization domain on the properties of soluble HIV-1 envelope glycoprotein trimers, uncleaved, soluble gp140 glycoproteins were stabilized by fusion with another trimeric motif derived from T4 bacteriophage fibritin. The fibritin construct was more stable to heat and reducing conditions than the GCN4 construct. Both GCN4- and fibritin-stabilized soluble gp140 glycoproteins exhibited patterns of neutralizing and nonneutralizing antibody binding expected for the functional envelope glycoprotein spike. Of note, two potently neutralizing antibodies, immunoglobulin G1b12 and 2G12, exhibited the greatest recognition of the stabilized, soluble trimers, relative to recognition of the gp120 monomer. The observed similarities between the GCN4 and fibritin constructs indicate that the HIV-1 envelope glycoprotein ectodomains dictate many of the antigenic and structural features of these fusion proteins. The melting temperatures and ligand recognition properties of the GCN4- and fibritin-stabilized soluble gp140 glycoproteins suggest that these molecules assume conformations distinct from that of the fusion-active, six-helix bundle.

Antibodies, Monoclonal↗
PubMed2002

Disc herniation after lumbar fusion.

STUDY DESIGN: Eight patients with a herniated disc after lumbar spinal fusion are reported. Their clinical features, imaging studies, and management are reported. OBJECTIVES: To identify the incidence and features of disc herniation above a spinal fusion, and to describe their management. SUMMARY OF BACKGROUND DATA: Late complications of lumbar spinal fusions have been reported in the literature, but disc herniation has not been specifically addressed in detail. The motion segment above a spinal fusion undergoes additional stresses, as documented by increased pressure and excessive motion, resulting in degenerative changes. These factors likely predispose to disc herniation. METHODS: Of 601 consecutive lumbar fusion cases over an 8-year period, herniated nucleus pulposus above the fusion was diagnosed in 8 patients. The clinical findings and imaging studies were reviewed, including a myelogram computed tomography scan, a magnetic resonance image with positive documentation of the herniation, or both. The management of these cases was reviewed. RESULTS: Eight patients (1.3%) (4 men and 4 women) were identified, whose average age was 56.4 years. Nonoperative treatment failed in six patients. Two of these patients underwent simple discectomy, and the remaining four underwent discectomy and fusion. All four patients went on to fusion. The average time from disc herniation onset to fusion was 28.4 months. CONCLUSIONS: Herniated disc after lumbar spinal fusion was found in approximately 1.3% of patients. Although rare, this entity that should be considered when patients complain of recurring back pain after a lumbar spinal fusion.

Adult↗
PubMed1991

Selection of lumbar fusion levels in adult idiopathic scoliosis patients.

Fifty-three adult idiopathic scoliosis patients whose fusions ended caudally between L2 and S1 were reviewed relative to criteria for selection of the lowest fused vertebra and their outcome. The Harrington stable zone, central sacral line, and the presence of rotary subluxation, arthritis, spondylolisthesis, vertebral body and disc space wedging were studied. Preoperative and postoperative pain, quality of life, and decisions for surgery were surveyed with a 94% response. Results showed the older the patient, the lower the fusion. The Harrington stable zone was useful, whereas the central sacral line frequently indicated longer fusions by as much as three segments. The presence of pathoanatomic features also dictated lower fusions. Patients in whom the lowest level of fusion was consistent with selection criteria had reduced frequency and intensity of low-back pain.

Adult↗
PubMed2005

Identification and characterization of the putative fusion peptide of the severe acute respiratory syndrome-associated coronavirus spike protein.

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is a newly identified member of the family Coronaviridae and poses a serious public health threat. Recent studies indicated that the SARS-CoV viral spike glycoprotein is a class I viral fusion protein. A fusion peptide present at the N-terminal region of class I viral fusion proteins is believed to initiate viral and cell membrane interactions and subsequent fusion. Although the SARS-CoV fusion protein heptad repeats have been well characterized, the fusion peptide has yet to be identified. Based on the conserved features of known viral fusion peptides and using Wimley and White interfacial hydrophobicity plots, we have identified two putative fusion peptides (SARS(WW-I) and SARS(WW-II)) at the N terminus of the SARS-CoV S2 subunit. Both peptides are hydrophobic and rich in alanine, glycine, and/or phenylalanine residues and contain a canonical fusion tripeptide along with a central proline residue. Only the SARS(WW-I) peptide strongly partitioned into the membranes of large unilamellar vesicles (LUV), adopting a beta-sheet structure. Likewise, only SARS(WW-I) induced the fusion of LUV and caused membrane leakage of vesicle contents at peptide/lipid ratios of 1:50 and 1:100, respectively. The activity of this synthetic peptide appeared to be dependent on its amino acid (aa) sequence, as scrambling the peptide rendered it unable to partition into LUV, assume a defined secondary structure, or induce both fusion and leakage of LUV. Based on the activity of SARS(WW-I), we propose that the hydrophobic stretch of 19 aa corresponding to residues 770 to 788 is a fusion peptide of the SARS-CoV S2 subunit.

Amino Acid Sequence↗