Location and chemical synthesis of a pre-S gene coded immunodominant epitope of hepatitis B virus

Immunodominant, disulfide-bond independent epitopes recognized by human antibodies to hepatitis B virus (HBV) are located within the 55-residue amino terminal portion (coded for by the pre-S region of HBV DNA) of minor HBV envelope components larger than the major protein constituents encoded by the S gene. A peptide having the sequence of the first 26 amino acids from the amino terminal methionine was synthesized and elicited antibodies (at dilutions of greater than or equal to 1 to 10(5) ) to the HBV envelope. These antibodies can be utilized for diagnostic tests. The immunogenicity of the peptide was substantially increased by covalent attachment to liposomes. The disulfide bond-independent determinants on sequences coded for by the pre-S gene may be more easily mimicked by peptide analogs than "conformational" determinants on the S-gene product.     

Corrections and clarifications

In the report "Homozygous human TAP peptide transporter mutation in HLA class I deficiency" by H. de la Salle et al. (8 July, p. 237), figure 2B (p. 239) was printed incorrectly. The correct figure appears below.     

Dahllite Identified as a Constituent of Prodissoconch I of Pinctada martensii (Dunker)

It has been brought to our attention that we did not designate the correct collectors of several of the samples reported in "Lamont radiocarbon measurements III" [Science 124, 154 (27 July 1956)]. The following list gives the proper collectors for several samples in Table 4 under V. Arctic studies: L192B, R. D. Cotell (1952); L261A,B,C, G. Hattersley-Smith (1953); L254A, L248A, R. L. Christie (1954); L254B,C,D, E. W. Marshall (1954); and L248B, G. Hattersley-Smith and A. P. Crary (1954).     

Autologous red cell agglutination assay for HIV-1 antibodies: simplified test with whole blood

An antibody detection procedure based on agglutination of autologous red cells has been developed for samples of whole blood. A nonagglutinating monoclonal antibody to human red blood cells conjugated to a synthetic peptide antigen (in this case residues 579 to 601 of the HIV-1 envelope precursor, Arg-Ile-Leu-Ala-Val-Glu-Arg-Tyr-Leu-Lys-Asp-Gln-Gln-Leu-Leu-Gly-Ile-Trp- Gly-Cys - Ser-Gly-Lys) permitted the detection of antibodies to the human immunodeficiency virus type 1 (HIV-1) in 10 microliters of whole blood within 2 minutes. Agglutination was specifically inhibited by addition of synthetic peptide antigen but not by unrelated peptides. The frequency of false positive results was 0.1% with HIV-1 seronegative blood donors (n = 874). The false negative results were approximately 1% (n = 81). The autologous red cell agglutination test is potentially suitable for simple, rapid, qualitative screening for antibodies to a variety of antigens of medical and veterinary diagnostic significance.     

Stimulation of gonadotropin release by a non-GnRH peptide sequence of the GnRH precursor

The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture. The peptide did not affect thyrotropin or prolactin secretion. A GnRH antagonist did not inhibit gonadotropin stimulation by the peptide, and the peptide did not compete with GnRH for GnRH pituitary receptors, indicating that the action of the peptide is independent of the GnRH receptor. The GnRH precursor contains two distinct peptide sequences capable of stimulating gonadotropin release from human and baboon pituitary cells.     

Convergent solutions to binding at a protein-protein interface

The hinge region on the Fc fragment of human immunoglobulin G interacts with at least four different natural protein scaffolds that bind at a common site between the C(H2) and C(H3) domains. This "consensus" site was also dominant for binding of random peptides selected in vitro for high affinity (dissociation constant, about 25 nanomolar) by bacteriophage display. Thus, this site appears to be preferred owing to its intrinsic physiochemical properties, and not for biological function alone. A 2.7 angstrom crystal structure of a selected 13-amino acid peptide in complex with Fc demonstrated that the peptide adopts a compact structure radically different from that of the other Fc binding proteins. Nevertheless, the specific Fc binding interactions of the peptide strongly mimic those of the other proteins. Juxtaposition of the available Fc-complex crystal structures showed that the convergent binding surface is highly accessible, adaptive, and hydrophobic and contains relatively few sites for polar interactions. These are all properties that may promote cross-reactive binding, which is common to protein-protein interactions and especially hormone-receptor complexes.     

Systemic lupus erythematosus: presence in human serum of an unusual acid-labile leukocyte interferon

A previously undescribed species of human leukocyte, or alpha, interferon is present in the serum of many patients with systemic lupus erythematosus. It was shown to be alpha-interferon by neutralization with specific antiserums, affinity column chromatography, and antiviral activity on bovine cells. However, 23 of 30 interferon samples tested were inactivated by incubation at pH 2, a characteristic of human "immune," or gamma, interferon. Multiple samples of interferon from the same patient had similar biological properties, but samples from different patients were not all identical, suggesting that several variants of this species of human alpha-interferon may exist.     

Highly conserved protective epitopes on influenza B viruses

Identification of broadly neutralizing antibodies against influenza A viruses has raised hopes for the development of monoclonal antibody-based immunotherapy and "universal" vaccines for influenza. However, a substantial part of the annual flu burden is caused by two cocirculating, antigenically distinct lineages of influenza B viruses. Here, we report human monoclonal antibodies, CR8033, CR8071, and CR9114, that protect mice against lethal challenge from both lineages. Antibodies CR8033 and CR8071 recognize distinct conserved epitopes in the head region of the influenza B hemagglutinin (HA), whereas CR9114 binds a conserved epitope in the HA stem and protects against lethal challenge with influenza A and B viruses. These antibodies may inform on development of monoclonal antibody-based treatments and a universal flu vaccine for all influenza A and B viruses.     

Human leukocyte antigenic specificity HL-A3: frequency of occurrence

Reactivity of antiserum against HL-A3, a human leukocyte and tissue antigenic specificity, depends upon a property of the lymphocyte as well as on the potency of the serum. Many reactions of HL-A3 antiserums can only be recognized through absorption or by a two-stage test not in general use. Interpretations of donor-recipient compatibility and of the constitution of HL-A alleles affected by these findings.     

Structure of complex of synthetic HIV-1 protease with a substrate-based inhibitor at 2.3 A resolution

The structure of a complex between a peptide inhibitor with the sequence N-acetyl-Thr-Ile-Nle-psi[CH2-NH]-Nle-Gln-Arg.amide (Nle, norleucine) with chemically synthesized HIV-1 (human immunodeficiency virus 1) protease was determined at 2.3 A resolution (R factor of 0.176). Despite the symmetric nature of the unliganded enzyme, the asymmetric inhibitor lies in a single orientation and makes extensive interactions at the interface between the two subunits of the homodimeric protein. Compared with the unliganded enzyme, the protein molecule underwent substantial changes, particularly in an extended region corresponding to the "flaps" (residues 35 to 57 in each chain), where backbone movements as large as 7 A are observed.     

Chlamydia infections and heart disease linked through antigenic mimicry

Chlamydia infections are epidemiologically linked to human heart disease. A peptide from the murine heart muscle-specific alpha myosin heavy chain that has sequence homology to the 60-kilodalton cysteine-rich outer membrane proteins of Chlamydia pneumoniae, C. psittaci, and C. trachomatis was shown to induce autoimmune inflammatory heart disease in mice. Injection of the homologous Chlamydia peptides into mice also induced perivascular inflammation, fibrotic changes, and blood vessel occlusion in the heart, as well as triggering T and B cell reactivity to the homologous endogenous heart muscle-specific peptide. Chlamydia DNA functioned as an adjuvant in the triggering of peptide-induced inflammatory heart disease. Infection with C. trachomatis led to the production of autoantibodies to heart muscle-specific epitopes. Thus, Chlamydia-mediated heart disease is induced by antigenic mimicry of a heart muscle-specific protein.     

Atrial natriuretic peptide elevation in congestive heart failure in the human

A sensitive radioimmunoassay for atrial natriuretic peptide was used to examine the relation between circulating atrial natriuretic peptide and cardiac filling pressure in normal human subjects, in patients with cardiovascular disease and normal cardiac filling pressure, and in patients with cardiovascular disease and elevated cardiac filling pressure with and without congestive heart failure. The present studies establish a normal range for atrial natriuretic peptide in normal human subjects. These studies also establish that elevated cardiac filling pressure is associated with increased circulating concentrations of atrial natriuretic peptide and that congestive heart failure is not characterized by a deficiency in atrial natriuretic peptide, but with its elevation.     

抗苏云金芽孢杆菌Cry1B毒蛋白质单链抗体的筛选与鉴定

利用人源化噬菌体抗体库筛选抗Bt Cry1B毒蛋白质的单链抗体(Single-chain antibodies,scFv)。将扩增后的噬菌体抗体库与固相化包被的Cry1B毒蛋白质特异性结合,经4轮"吸附-洗脱-扩增"后,富集特异性识别Cry1B毒蛋白质的噬菌体单链抗体。从最后一轮筛选中随机挑取单菌落进行单克隆ELISA鉴定,对阳性克隆进行PCR扩增、DNA电泳鉴定及测序,成功筛选获得8个阳性噬菌体scFvs,经鉴定均有完整外源基因片段插入。挑取阳性值最高的scFv(1E2)建立了基于单链抗体的Cry1B毒蛋白质间接竞争ELISA检测方法。结果表明,Cry1B毒蛋白质对噬菌体scFv(1E2)的抑制中浓度(IC50)为1.075μg/ml,最低检测限(IC10)为0.013 4μg/ml,线性检测范围在0.5μg/ml至4.0μg/ml之间。     

The atomic structure of Mengo virus at 3.0 A resolution

The structure of Mengo virus, a representative member of the cardio picornaviruses, is substantially different from the structures of rhino- and polioviruses. The structure of Mengo virus was solved with the use of human rhinovirus 14 as an 8 A resolution structural approximation. Phase information was then extended to 3 A resolution by use of the icosahedral symmetry. This procedure gives promise that many other virus structures also can be determined without the use of the isomorphous replacement technique. Although the organization of the major capsid proteins VP1, VP2, and VP3 of Mengo virus is essentially the same as in rhino- and polioviruses, large insertions and deletions, mostly in VP1, radically alter the surface features. In particular, the putative receptor binding "canyon" of human rhinovirus 14 becomes a deep "pit" in Mengo virus because of polypeptide insertions in VP1 that fill part of the canyon. The minor capsid peptide, VP4, is completely internal in Mengo virus, but its association with the other capsid proteins is substantially different from that in rhino- or poliovirus. However, its carboxyl terminus is located at a position similar to that in human rhinovirus 14 and poliovirus, suggesting the same autocatalytic cleavage of VP0 to VP4 and VP2 takes place during assembly in all these picornaviruses.     

枯草芽孢杆菌分泌载体构建及其对脂肪酶A的分泌表达

[目的]构建含不同信号肽编码序列的枯草芽孢杆菌分泌表达载体,并研究这些载体对脂肪酶A的分泌表达效率。[方法]克隆得到枯草芽孢杆菌168株的脂肪酶A编码基因,同时扩增得到蛋白质NprE、Bpr、YweA的信号肽编码序列,构建了脂肪酶A分泌表达载体pMA5-estA、pMA5-nprE-estA、pMA5-bpr-estA和pMA5-yweA-estA,并转化到枯草芽孢杆菌168株中得到相应的重组分泌表达菌株。[结果]对4株重组表达菌株进行摇瓶培养,所有菌株都实现了脂肪酶A的分泌,20 h后,168（pMA5-bpr-estA）的细胞外脂肪酶A的酶活力达到1.68 U/ml,约占该菌株脂肪酶A总表达量的86%。[结论]枯草芽孢杆菌Bpr信号肽对脂肪酶A具有较高的分泌效率。     

Diagnostic potential for human malignancies of bacterially produced HTLV-I envelope protein

Two regions of the gene for the human T-cell leukemia virus subgroup I (HTLV-I) envelope were expressed in Escherichia coli by use of the vector pJLA16. One corresponds to the carboxyl terminal region of the major envelope protein p46, and the other corresponds to the transmembrane protein p21E. Reactivity of the expressed protein with human serum was tested by the Western blot procedure. Each of 11 sera tested that had been shown to contain antibodies to HTLV-I or HTLV-II by an enzyme-linked immunosorbent assay recognized the bacterially synthesized envelope proteins. There was no reaction detected when 17 control sera were tested. This system will be useful for large-scale seroepidemiological surveys for HTLV-I and related human retroviruses.     

Adult hemoglobin synthesis by reticulocytes from the human fetus at midtrimester

The synthesis of adult-type hemoglobin was measured in small samples of peripheral blood cells from 9- to 18-week human fetuses. Hemoglobin indistinguishable from hemoglobin A was identified by ion-exchange chromatography, electrophoresis at pH 8.6, tryptic peptide analysis, and the insensitivity of its synthesis to the action of O-methylthreonine. Synthesis of hemoglobin A accounted for 8 to 14 percent of total hemoglobin synthesis and was demonstrated in as little as 10 microliters of fetal blood. These studies provide sensitive methods for the detection of beta chain types in hemoglobin synthesized by the human fetus at midtrimester. If methods to obtain small quantities of fetal blood at midtrimester become available, these techniques should be applicable to the antenatal detection of sickle cell anemia and related hemoglobinopathies.     

Structure and expression of a complementary DNA for the nuclear coded precursor of human mitochondrial ornithine transcarbamylase

Most mitochondrial proteins are encoded in the nucleus and are translated on free cytoplasmic ribosomes as larger precursors containing amino-terminal "leader" sequences, which are removed after the precursors are taken up by mitochondria. We have deduced the complete primary structure of the precursor of a human mitochondrial matrix enzyme, ornithine transcarbamylase (OTC), from the nucleotide sequence of cloned complementary DNA. The amino-terminal leader peptide of OTC is 32 amino acids in length and contains four arginines but no acidic residues. Cleavage of the leader peptide from the "mature" protein occurs between glutamine and asparagine residues. The sequence of mature human OTC resembles that of the subunits of both OTC and aspartate transcarbamylase from Escherichia coli. The biological activity of the cloned OTC complementary DNA was tested by joining it with SV40 (an animal virus) regulatory elements and transfecting cultured HeLa cells, which do not normally express OTC. Both the precursor and mature forms of the OTC subunit were identified; in stable transformants, enzymatic activity was also detected.     

Recombinant human granulocyte colony-stimulating factor: effects on normal and leukemic myeloid cells

Experiments were conducted to isolate and characterize the gene and gene product of a human hematopoietic colony-stimulating factor with pluripotent biological activities. This factor has the ability to induce differentiation of a murine myelomonocytic leukemia cell line WEHI-3B(D+) and cells from patients with newly diagnosed acute nonlymphocytic leukemia (ANLL). A complementary DNA copy of the gene encoding a pluripotent human granulocyte colony-stimulating factor (hG-CSF) was cloned and expressed in Escherichia coli. The recombinant form of hG-CSF is capable of supporting neutrophil proliferation in a CFU-GM assay. In addition, recombinant hG-CSF can support early erythroid colonies and mixed colony formation. Competitive binding studies done with 125I-labeled hG-CSF and cell samples from two patients with newly diagnosed human leukemias as well as WEHI-3B(D+) cells showed that one of the human leukemias (ANLL, classified as M4) and the WEHI-3B(D+) cells have receptors for hG-CSF. Furthermore, the murine WEHI-3B(D+) cells and human leukemic cells classified as M2, M3, and M4 were induced by recombinant hG-CSF to undergo terminal differentiation to macrophages and granulocytes. The secreted form of the protein produced by the bladder carcinoma cell line 5637 was found to be O-glycosylated and to have a molecular weight of 19,600.