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T D Copeland

Publications and source records attributed to T D Copeland.

At least 127 records · Page 7Linked to original sources
PubMed1985

Monoclonal antibodies reactive with human T cell lymphotropic virusI (HTLVI) p19 internal core protein: cross-reactivity with normal tissues and differential reactivity with HTLV types I and II.

Three monoclonal antibodies to human T cell lymphotropic virus type I (HTLVI) p19 internal core protein, designated as alpha HTLV-2, 3, and 4, have been developed. In indirect immunofluorescence (IF) assays, these antibodies reacted with acetone-fixed cytocentrifuge preparations of culture HTLVI-infected peripheral blood leukocyte (PBL) from a patient (SD) with Japanese adult T cell leukemia and with infected HUT-102 T cells but not with cultured normal PBL. Anti-p19 antibodies alpha HTLV-2, 3, and 4 all reacted with the same HTLVI p19 identified both by antibodies in HTLVI+ patient sera and by antisera raised against two synthetic peptides encoded by the p19 gag region of HTLVI. Partial proteolytic cleavage of p19 immunoprecipitates obtained with antibodies alpha HTLV-2, 3, and 4 produced a 17,000-dalton cleavage product, in agreement with the size of the fragment predicted from the nucleic acid sequence of the HTLVI p19 gag region. Antibodies alpha HTLV-3 and 4 reacted with HTLVI but not HTLVII proteins and were useful diagnostic probes in identifying HTLVI- but not HTLVII-infected lymphoid cells in immunofluorescence assays. In addition to reacting with HTLVI p19, antibodies 2 and 4 also cross-reacted with a wide variety of HTLV-uninfected normal and neoplastic cells and tissues. In addition, HTLVI+ patient sera contained antibodies that competed for binding to the antigenic site on p19 recognized by antibody 4. Thus, anti-p19 monoclonal antibodies alpha HTLV-2 and 4 reacted with a 19,000-dalton viral-encoded protein of HTLVI and cross-reacted with normal host tissues, while anti-p19 antibody alpha HTLV-3 was specific for HTLVI p19 core protein.

Animals↗
PubMed1984

The envelope proteins of bovine leukemia virus: purification and sequence analysis.

Two proteins, termed gp60 and p30, have been purified to homogeneity from bovine leukemia virus (BLV) using controlled pore glass and reverse-phase liquid chromatography (RPLC). gp60 was shown to be a glycoprotein by identification of glucosamine on the amino acid analyzer. Antiserum prepared to gp60 recognized in addition to gp60 a 52,000-Da polypeptide in some virus preparations, but did not cross-react with p30. The amino and carboxyl termini of gp60 were found to be tryptophan and arginine, respectively, and a 38-residue amino-terminal sequence of gp60 (NH2TrpArgXSerLeuSerLeuGlyAsnGlnGlnTrpMetThrAlaTyrAsnGlnGluAlaLys PheSerIleSerIleAspGlnIleLeuGluAlaHisAsnGlnSerProPhe-) was obtained. A 12-residue amino-terminal sequence for p30 (NH2SerProValAlaAlaLeuThrLeuGlySerAlaLeu) was also obtained. The p30 sequence showed substantial homology to the transmembrane proteins of both types B and C retroviruses and also to a deduced sequence of the 3' region of the env gene of human T-cell leukemia virus. From these results and from elution behavior of these proteins on RPLC, it was concluded that gp60 and p30 are the BLV env gene-encoded surface glycoprotein and transmembrane protein, respectively.

Amino Acid Sequence↗
PubMed1984

Complete amino acid sequence of the basic nucleic acid binding protein of feline leukemia virus.

The complete amino acid sequence of the nucleic acid binding protein p10 of the Rickard strain of feline leukemia virus (FeLV) has been determined. Fragments obtained by enzymatic digestion were purified by reverse-phase liquid chromatography and subjected to semiautomated Edman degradation. FeLV p10 is a basic polypeptide composed of 57 amino acids with Mr = 6604. The structure of p10 is compared to the structures of other retroviral nucleic acid binding proteins, and an analysis of a highly conserved region, the putative binding domain, is presented.

Amino Acid Sequence↗
PubMed1984

Quantitative separation of murine leukemia virus proteins by reversed-phase high-pressure liquid chromatography reveals newly described gag and env cleavage products.

The structural proteins of murine type C retroviruses are proteolytic cleavage products of two different precursor polyproteins coded by the viral gag and env genes. To further investigate the nature and number of proteolytic cleavages involved in virus maturation, we quantitatively isolated the structural proteins of the Rauscher and Moloney strains of type C murine leukemia virus (R-MuLV and M-MuLV, respectively) by reversed-phase high-pressure liquid chromatography. Proteins and polypeptides isolated from R-MuLV included p10, p12, p15, p30, p15(E), gp69, and gp71 and three previously undescribed virus components designated here as p10', p2(E), and p2(E). Homologous proteins and polypeptides were isolated from M-MuLV. Complete or partial amino acid sequences of all the proteins listed above were either determined in this study or were available in previous reports from this laboratory. These data were compared with those from the translation of the M-MuLV proviral DNA sequence (Shinnick et al., Nature [London] 293:543-548, 1981) to determine the exact nature of proteolytic cleavages for all the structural proteins described above and to determine the origin of p10' and p2(E)s. The results showed that, during proteolytic processing of gp80env from M-MuLV (M-gp 80env), a single Arg residue was excised between gp70 and p15(E) and a single peptide bond was cleaved between p15(E) and p2(E). The structure of M-gPr80env is gp70-(Arg)-p15(E)-p2(E). The data suggest that proteolytic cleavage sites in R-gp85env are identical to corresponding cleavage sites in M-gp80env. The p2(E)s are shown to be different genetic variants of p2(E) present in the uncloned-virus preparations. The data for R- and M-p10's shows that they are cleavage products of the gag precursor with the structure p10-Thr-Leu-Asp-Asp-OH. The complete structure of Pr65gag is p15-p12-p30-p10'. Stoichiometries of the gag and env cleavage products in mature R- and M-MuLV were determined. In each virus, gag cleavage products (p15, p12, p30, and p10 plus p10') were found in equimolar amounts and p15(E)s were equimolar with p2(E)s. The stoichiometry of gag to env cleavage products was 4:1. These data are consistent with the proposal that proteolytic processing of precursor polyproteins occurs after virus assembly and that the C-terminal portion of Pr15(E) [i.e., p15(E)-p2(E)] is located on the inner side of the lipid bilayer of the virus.

Amino Acid Sequence↗
PubMed1984

Structural and antigenic characterization of the proteins of human T-cell leukemia viruses and their relationships to the gene products of other retroviruses.

The primary structure analysis of the gag gene products of human T-cell leukemia virus (HTLV)-ICR has been nearly completed. A comparison of the amino acid sequences with the published nucleotide sequence of HTLV-IATK established that i) p19 which is known to share antigenic determinants with a protein present in normal thymic epithelium, is nevertheless virally coded. ii) The gene order and complete primary structure of the gag precursor (Pr55) which has been shown to be myristylated (My) at its N-terminus is My-p19-p24-p15-OH; and iii) the Pr55gag amino acid sequences of HTLV-ICR and HTLV-IATK are nearly identical showing only a single residue difference in the C-terminal region of p15. Antibodies to synthetic peptides inferred from the nucleotide sequence of the env gene of HTLV-IATK were also raised and used to identify and purify env precursor gPr62-68, surface glycoprotein gp46-51 and transmembrane protein p21. While most of the peptide sera were shown to be subgroup specific some of them detected antigenic determinants shared between protein homologs of viruses of subgroups I and II. Partial or complete amino acid sequences of both the gag and env gene coded proteins of bovine leukemia virus (BLV) structural proteins have also been determined. These extensive protein data together with nucleotide sequences confirm and extend our initial finding that HTLV and BLV are structurally and antigenically related and may have originated from common ancestor. The structural and immunological studies revealed also relationships between HTLV and a number of type C and type D retroviruses studied. One of the highly conserved sequences is shared by the transmembrane proteins of these retroviruses which have been implicated in immunosuppression. It is conceivable that these common regions have common biological function. Two previously unidentified proteins of BLV have also been purified and structurally characterized. Nucleotide sequences capable of coding for related products are present in HTLV. The nature and possible biological functions of these new BLV proteins and the putative HTLV gene products will be discussed. The size and complexity of the genome of the replication competent retroviruses are similar but not identical. The 35S RNA of all replication competent helper viruses is divided into three genes encoding the viral structural proteins: the gag (group-specific antigen) gene codes for the internal structural proteins, the pol (polymerase) gene codes for the enzymes protease, reverse transcriptase and endonuclease and the env (envelope) gene codes for the proteins of the viral envelope.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1983

Complete amino acid sequence of human T-cell leukemia virus structural protein p15.

The complete amino acid sequence of human T-cell leukemia virus (HTLV) structural protein p15 has been determined. The intact protein and peptides generated by enzymatic digestion and acid cleavage were purified by reversed-phase liquid chromatography and subjected to semi-automated Edman degradation. HTLV p15 is a basic linear polypeptide composed of 85 amino acids with Mr 9458. The primary structure indicates that HTLV p15 is homologous to the nucleic acid binding proteins of other type-C retroviruses and especially related to bovine leukemia virus p12.

Amino Acid Sequence↗
PubMed1983

Complete amino acid sequence of the nucleic acid-binding protein of bovine leukemia virus.

The complete amino acid sequence of the nucleic acid-binding protein p12 of bovine leukemia virus (BLV) has been determined. Peptides were generated by enzymatic digestion and formic acid cleavage, purified by reversed-phase liquid chromatography and subjected to automated Edman degradation. BLV p12 is a proline-rich linear polypeptide composed of 69 amino acids with Mr 7558. A comparison of the p12 structure to that of the avian and murine type C retroviral nucleic acid-binding proteins shows significant homology only in the putative binding domain. This conserved region is duplicated BLV p12 as in the avian homolog.

Amino Acid Sequence↗
PubMed1983

Structural and antigenic analysis of the nucleic acid-binding proteins of bovine and feline leukemia viruses.

The nucleic acid-binding proteins of bovine leukemia virus (BLV) and feline leukemia virus (FeLV) were isolated in a high state of purity with chloroform-methanol extraction followed by reversed-phase liquid chromatography. Selective solubilization and purity of BLV p12 and FeLV p10 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The compositions and molecular weights were determined by amino acid analysis. An abundance of lysine and arginine residues along with their size identifies both BLV p12 and FeLV p10 as small basic proteins similar to well-defined type C viral nucleoproteins. NH2-terminal degradation by the semiautomated Edman method provided the sequence of the first 40 amino acids for both proteins. The putative nucleic acid binding site found in several type C viral nucleoproteins was contained within this sequence, with the most homology centered around an eight-amino acid region involving seven identical residues and one substitution. Antisera were developed in rabbits, and specificity and titers were determined by electroblotting and immunoautoradiography. By this technique, an immunological cross-reaction was found between BLV p12 and FeLV p10. The shared antigenic determinant most likely exists in the highly conserved eight-amino acid region. Although this sequence is also highly conserved in the nucleic acid-binding proteins of murine leukemia viruses, the shared antigenic determinant is not found in these or any other type C viruses tested. It is suggested that substitution of arginine (BLV p12/FeLV p10) to lysine (murine leukemia virus p10) is sufficient to elicit a change in antibody specificity.

Amino Acid Sequence↗
PubMed1983

Biologic properties of homogeneous interleukin 3. I. Demonstration of WEHI-3 growth factor activity, mast cell growth factor activity, p cell-stimulating factor activity, colony-stimulating factor activity, and histamine-producing cell-stimulating factor activity.

Interleukin 3 (IL 3) was initially defined as a factor in conditioned media from concanavalin A-stimulated lymphocytes (Con A CM) that induces the enzyme 20-alpha-hydroxysteroid dehydrogenase (20 alpha SDH) in cultures of nu/nu splenic lymphocytes. To determine the spectrum of additional "biologic" activities, IL 3 was purified to homogeneity and its properties were assessed. The protein preparation was judged to be homogeneous IL 3 by the following criteria: 1) elution of a peak of IL 3 with a constant specific activity in the last step of purification, 2) presence of a single protein by SDS-PAGE analysis, 3) receptor-binding activity against IL 3-dependent cell lines, 4) a specific activity of congruent to 0.2 ng/ml required for 50% of maximal biologic activity, and 5) the presence of a single amino terminal sequence. With the use of this preparation of IL 3, the dose-response curves for 20 alpha SDH induction were identical or similar to the dose-response curves for the activities of 1) WEHI-3 growth factor, 2) mast cell growth factor, 3) P cell-stimulating factor, and 4) histamine-producing cell-stimulating factor. In addition, homogeneous IL 3 had colony-stimulating factor activity, although only approximately 2% of the total CSF activity found in Con A CM was associated with IL 3. The major peak of CSF activity could be resolved from IL 3 by DEAE column chromatography and lacked many of the biologic activities associated with IL 3.

Animals↗
PubMed1982

Complete amino acid sequence of the group-specific antigen gene-encoded phosphorylated proteins of mouse leukemia viruses.

The complete amino acid sequence of the group-specific antigen gene-encoded RNA binding phosphoprotein p12 has been determined for both Rauscher and Moloney leukemia viruses. Large fragments generated by acid, and cyanogen bromide and hydroxylamine cleavage, and Staphylococcus aureus V8 protease digestion were subjected to automated sequencing. Both Rauscher and Moloney p12 are composed of 84 amino acids arranged in alternating variable and conserved regions. The homology between the conserved internal and COOH-terminal regions is greater than 95%, but the NH2-terminal and internal variable regions show 59 and 51% homology, respectively. The role of such regions in the type-specific biological activities of these molecules is discussed.

Amino Acid Sequence↗
PubMed1982

Primary structure analysis of the major internal protein p24 of human type C T-cell leukemia virus.

A human type C retrovirus [human T-cell leukemia (lymphoma) virus; HTLV], recently isolated from young adult patients with cutaneous T-cell lymphoma or leukemia, was not detectably related to other known animal retroviruses in molecular hybridization studies, by comparison of reverse transcriptase and the major core protein p24. The p24 core protein was purified to homogeneity. The amino acid composition, the COOH-terminal amino acid, and the NH(2)-terminal amino acid sequence of the first 25 residues of this major internal structural protein were determined. These results were then compared to the known structure of the internal core protein of other retroviruses. The compositional data reveal that HTLV p24 is chemically distinct from p30-p24 of other animal retroviruses, in agreement with the earlier immunological analyses. However, HTLV p24 shares the common NH(2)-terminal proline and COOH-terminal leucine of all mammalian type C viral p30s. In addition, like bovine leukemia virus (BLV), HTLV lacks the common prolylleucylarginine tripeptide and the larger conserved region found near the NH(2) terminus of the other mammalian type C viral p30s. Alignment of the amino acid sequence of HTLV p24 with previously determined sequences of other retrovirus proteins, including BLV p24, reveals statistically significant sequence homology only to BLV. The results reported here demonstrate that HTLV p24 is related to but chemically distinct from the major core protein of other retroviruses. Similarly, previous results showed that there was no immunological crossreactivity of the p24 protein and reverse transcriptase of HTLV with other retroviruses, including BLV, and no nucleic acid sequence homology. However, the present results, combined with the common size of the p24 and reverse transcriptase, suggest that HTLV may be closer to BLV than any other known retrovirus.

Amino Acid Sequence↗
PubMed1982

Processing and amino acid sequence analysis of the mouse mammary tumor virus env gene product.

The envelope proteins of mouse mammary tumor virus (MMTV) are synthesized from a subgenomic 24S mRNA as a 75,000-dalton glycosylated precursor polyprotein which is eventually processed to the mature glycoproteins gp52 and gp36. In vivo synthesis of this env precursor in the presence of the core glycosylation inhibitor tunicamycin yielded a precursor of approximately 61,000 daltons (P61env). However, a 67,000-dalton protein (P67env) was obtained from cell-free translation with the MMTV 24S mRNA as the template. To determine whether the portion of the protein cleaved from P67env to give P61env was removed from the NH2-terminal end of P67env and as such would represent a leader sequence, the NH2-terminal amino acid sequence of the terminal peptide gp52 was determined. Glutamic acid, and not methionine, was found to be the amino-terminal residue of gp52, indicating that the cleaved portion was derived from the NH2-terminal end of P67env. The NH2-terminal amino acid sequences of gp52's from endogenous and exogenous C3H MMTVs were determined though 46 residues and found to be identical. However, amino acid composition and type-specific gp52 radioimmunoassays from MMTVs grown in heterologous cells indicated primary structure differences between gp52's of the two viruses. The nucleic acid sequence of cloned MMTV DNA fragments (J. Majors and H. E. Varmus, personal communication) in conjunction with the NH2-terminal sequence of gp52 allowed localization of the env gene in the MMTV genome. Nucleotides coding for the NH2 terminus of gp52 begin approximately 0.8 kilobase to the 3' side of the single EcoRI cleavage site. Localization of the env gene at that point agrees with the proposed gene order -gag-pol-env- and also allows sufficient coding potential for the glycoprotein precursor without extending into the long terminal repeat.

Amino Acid Sequence↗
PubMed1981

Primary structure of the low molecular weight nucleic acid-binding proteins of murine leukemia viruses.

Murine leukemia viruses contain a low molecular weight basic protein, designated p10, which binds to single-stranded nucleic acids. The complete amino acid sequence of p10 from the Rauscher strain of virus has been determined. The partial amino acid sequences of p10s from Moloney, Friend, AKR, Gross, radiation leukemia, and BALB/2 viral strains have also been determined using microsequencing techniques. Rauscher p10 is composed of 56 amino acid residues; the other p10s are similar in size but differ from Rauscher by a few conservative amino acid substitutions. The structure of Rauscher p10 was compared to the structure of a functionally homologous protein from Rous avian sarcoma virus. The comparison revealed regions of amino acid sequence homologies which indicate a phylogenetic relationship between the murine and avian viral strains. The analyses revealed a periodic placement of three Cys residues and a Gly-His sequence. A structure involving these residues is found once in the murine protein and twice in the avian protein. A similar structure is seen in the single stranded nucleic acid binding protein of bacteriophage T4. However, in the latter case, the order of amino acid residues is inverted.

AKR murine leukemia virus↗
PubMed1981

Chemical and Immunological characterization of the major structural protein (p28) of MMC-1, a rhesus monkey endogenous type C virus: homology with the major structural protein of avian reticuloendotheliosis virus.

The major core protein (p28) of MMC-1, an endogenous type C virus of the rhesus monkey (Macaca mulatta), was purified and subjected to structural and immunological analyses. The NH2-terminal amino acid sequence of MMC-1 p28 showed extensive homology to the sequences of the major structural proteins (p30) of known mammalian type C viruses. Similarly, interspecies antigenic determinants shared by all the above viral proteins were detected in MMC-1 p28. Competition radioimmunoassays together with the results of statistical analysis of the primary structure data provided evidence that MMC-1 p28 is not more closely related to primate type C viruses of the Papio genus than to those isolated from rodents, cats, or New World monkeys. MMC-1 p28 was found to be closely related structurally to the p30 protein of the avian reticuloendotheliosis virus (REV-A), a horizontally transmitted type C virus of putative mammalian origin. In addition, MMC-1 p28 and REV-A p30 shared a specific subset of antigenic determinants not present in any of the other avian or mammalian type C viruses studied. These findings suggest that MMC-1 and REV may have a common evolutionary origin.

Amino Acid Sequence↗