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Tillet E, Wiedemann H, Golbik R, Pan TC, Zhang RZ, Mann K, Chu ML, Timpl R. Recombinant expression and structural and binding properties of alpha 1(VI) and alpha 2(VI) chains of human collagen type VI. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 221:177-85. [PMID: 8168508 DOI: 10.1111/j.1432-1033.1994.tb18727.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Full-length alpha 1(VI) and alpha 2(VI) cDNAs in an eukaryotic expression vector were used to obtain stably transfected human kidney cell clones and to purify these collagen-VI chains in substantial quantities from the culture medium. Both chains appeared mainly as monomers together with some dimers that were disulfide linked through their C-terminal globular domains. Despite sufficient hydroxylation of proline and lysine residues, the chains did not form a triple-helix, as shown by electronmicroscopy, CD spectra and pepsin sensitivity. Digestion of the chains with bacterial collagenase released the N-terminal and C-terminal globular domains, which were identified by their size and partial sequences. They showed a substantial content of alpha-helical conformation and a distinct globular structure after rotary shadowing. Antibodies could be raised that distinguished between the two chains and reacted with the globular domains. The alpha 2(VI) but not the alpha 1(VI) chain showed binding to a heparan sulfate proteoglycan (perlecan), fibronectin and pepsin-solubilized collagen VI. Purified globular domains did not bind these ligands indicating the localization of binding sites within the triple-helical domain. Both chains showed a distinct affinity for heparin but failed to bind to various collagen types.
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Pan TC, Sasaki T, Zhang RZ, Fässler R, Timpl R, Chu ML. Structure and expression of fibulin-2, a novel extracellular matrix protein with multiple EGF-like repeats and consensus motifs for calcium binding. J Cell Biol 1993; 123:1269-77. [PMID: 8245130 PMCID: PMC2119879 DOI: 10.1083/jcb.123.5.1269] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A new protein, fibulin-2, was predicted from sequence analysis of cDNA clones obtained from a mouse fibroblast library. This protein consists of a 1195-residue polypeptide preceded by a 26-residue signal peptide. The COOH-terminal region of 787 amino acids contained three anaphylatoxin-related segments (domain I), 11 EGF-like repeats (domain II), 10 of which had a consensus motif for calcium-binding, and a 115-residue globular domain III. Except for two additional EGF-like repeats, this COOH-terminal region showed 43% sequence identity with the previously described fibulin-1 (BM-90). The NH2-terminal 408 residues, unique to fibulin-2, showed no sequence homology to other known proteins and presumably form two additional domains that differ in their cysteine content. Recombinant fibulin-2 was produced and secreted by human cell clones as a disulfide-bonded trimer. Rotary shadowing visualized the protein as three 40-45 nm long rods which are connected at one end in a globe-like structure. No significant immunological cross-reaction could be detected between fibulin-1 and fibulin-2. Production of the fibulin-2 was demonstrated by Northern blots and radioimmunoassay in fibroblasts but not in several tumor cell lines. Together with the observation that the serum level of fibulin-2 is 1,000-fold lower than that of fibulin-1, the data indicate that these two isoforms are not always coordinately expressed. This is also suggested by Northern blots of tissue mRNAs and by immunofluorescence localizations using mouse tissues. The latter studies also demonstrated an extracellular localization for fibulin-2 in basement membranes and other connective tissue compartments.
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Abstract
Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Though extensive epidemiological study has implicated that high arsenic content in artesian well water of the endemic area bears some important connection with the disease, the etiology of the disease is still unknown. In this study, attention is paid to multielement determination in order to find out whether the trace elements in hair of Blackfoot disease patients are different from those of the controls. Experimental results indicate that the concentrations of As and Se in hair of patients are significantly higher than those of the controls, but Ca and Zn are significantly lower than those of the controls. The possible connection of these elements with the etiology of the disease is discussed.
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Pan TC, Horng CJ, Lin SR. [Study on urinary arsenic, lead and cadmium concentrations in a steel production workers]. GAOXIONG YI XUE KE XUE ZA ZHI = THE KAOHSIUNG JOURNAL OF MEDICAL SCIENCES 1993; 9:643-9. [PMID: 8046783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Lead and cadmium levels in urine specimens were determined simultaneously by polarographic method, and arsenic by hydride atomic absorption spectrophotometry. The urine specimens were pretreated with a mixed acid solution and ORTHO bilevel urine metal control and APG Setpoint standard were used to check the analytical accuracy. The results showed the total arsenic [As], lead [Pb], cadmium [Cd] levels in the production and the quality control workers, were significantly higher than those in the control. The results indicate the need for an immediate improvement in workplace ventilation and industrial hygiene practices.
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Pan TC, Horng CJ, Lin SR, Lin TH, Huang CW. Simultaneous determination of Zn, Cd, Pb, and Cu in urine of patients with blackfoot disease using anodic stripping voltammetry. Biol Trace Elem Res 1993; 38:233-41. [PMID: 7504941 DOI: 10.1007/bf02785308] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Blackfoot disease (BFD) is an endemic peripheral vascular disorder resulting in gangrene of the lower extremities, especially the feet, among residents in a limited area on the southwest coast of Taiwan. In the present study, the concentrations of zinc, cadmium, lead, and copper in urine of BFD patients with matched normal controls are investigated by differential pulse anodic stripping voltammetry (DPASV) on a hanging mercury drop electrode (HMDE). The analytical results indicate that urinary copper, cadmium, and lead of the BFD patients are significantly higher than those of the controls. In addition, the patients showed a significantly lower concentration of zinc in the urine than the normal controls. The possible connection of these elements with the etiology of the disease is discussed.
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Pan TC, Kluge M, Zhang RZ, Mayer U, Timpl R, Chu ML. Sequence of extracellular mouse protein BM-90/fibulin and its calcium-dependent binding to other basement-membrane ligands. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 215:733-40. [PMID: 8354280 DOI: 10.1111/j.1432-1033.1993.tb18086.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Partial sequence comparisons have recently indicated that two extracellular components, fibulin from human placenta and BM-90 from a basement-membrane-producing mouse tumor, are either identical or closely related proteins. In this study, a complete sequence analysis of mouse BM-90 cDNA showed a 539-residue N-terminal core structure (domains I and II), which was 85% identical with the same core structure of human fibulin. A 137-residue C-terminal sequence (domain III) was unique for BM-90 and could also be identified by Edman degradation. This suggested a novel splice product, variant D, which is characteristic for the mouse tumor. A second 117-residue C-terminal sequence (domain III) was identified in additional mouse cDNA clones and showed 91% identity with the region specific for variant C of fibulin. Northern blots using mouse cells demonstrated two mRNA species, 2.7 kb and 2.3 kb, which encoded the variants D and C, respectively. The sequence of BM-90/fibulin indicates the presence of nine epidermal-growth-factor-like repeats in the core domain-II structure, eight of which contain consensus motifs for calcium binding. This binding is apparently important for the interaction of BM-90 with laminin and nidogen and for some weaker interactions with collagen IV. Further binding of BM-90 was demonstrated to fibronectin and BM-90 itself, but did not depend on calcium. Major binding sites for BM-90 were identified at a C-terminal segment of laminin A chain and at the N-terminus of nidogen. The broad interaction repertoire of BM-90 is comparable to that of nidogen and both proteins may have similar roles as connecting elements in the extracellular matrix.
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Zhang RZ, Pan TC, Timpl R, Chu ML. Cloning and sequence analysis of cDNAs encoding the alpha 1, alpha 2 and alpha 3 chains of mouse collagen VI. Biochem J 1993; 291 ( Pt 3):787-92. [PMID: 8489506 PMCID: PMC1132437 DOI: 10.1042/bj2910787] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
cDNA clones encoding the alpha 1, alpha 2 and alpha 3 chains of mouse collagen VI have been isolated by screening cDNA libraries with the corresponding human probes. The composite cDNAs for the alpha 1, alpha 2, and alpha 3 chains are 2.5, 1.6 and 2.9 kb in size respectively. The alpha 1 and alpha 2 cDNAs encode the C-terminal portions of the chains as well as the entire 3'-untranslated regions, while the alpha 3 cDNAs encode a central segment of 959 amino acids flanking the triple-helical domain. The deduced amino acid sequences share 86-88% identity with the human counterparts and 67-73% identity with the chicken equivalents. Alignment of the deduced amino acid sequences of mouse, human and chicken collagens reveal that the key features of the protein, including the cysteine residues, imperfections in the Gly-Xaa-Xaa regions, Arg-Gly-Asp sequences and potential N-glycosylation sites, are mostly conserved.
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Muona P, Jaakkola S, Zhang RZ, Pan TC, Pelliniemi L, Risteli L, Chu ML, Uitto J, Peltonen J. Hyperglycemic glucose concentrations up-regulate the expression of type VI collagen in vitro. Relevance to alterations of peripheral nerves in diabetes mellitus. THE AMERICAN JOURNAL OF PATHOLOGY 1993; 142:1586-97. [PMID: 8494053 PMCID: PMC1886917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Electron microscopy of peripheral nerves obtained from two diabetic patients revealed large deposits of microfibrils and the presence of Luse bodies in the vicinity of perineurial cells. Microfibrils were found to accumulate also in the sciatic nerves of diabetic BB rats; these microfibrillar deposits were shown to contain type VI collagen by immunoelectron microscopy. Connective tissue cells cultured from rat sciatic nerves were exposed to high glucose concentrations. High glucose concentrations up-regulated the mRNA steady-state levels of alpha 1(VI), alpha 2(VI), and alpha 3(VI) chains of type VI collagen and caused accumulation of type VI collagen-containing fibrils in the cultures. Immunostaining and in situ hybridizations demonstrated that perineurial cells, Schwann cells, and fibroblasts expressed type VI collagen at the mRNA and protein levels. The results suggest that the turnover and supramolecular assembly of type VI collagen are perturbed in diabetic nerves and that glucose per se increases the expression of type VI collagen in vitro.
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Pan TC, Zhang BG, Ge YX, Zhao JP, Shen YZ. Surgical treatment of double-chamber right ventricle and its associated anomalies. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1992; 12:250-2. [PMID: 1289576 DOI: 10.1007/bf02887860] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A report on the results of surgical treatment of 5 cases of DCRV and its associated anomaly was presented in this paper. No definite diagnosis of DCRV was made prior to operation. It was found that 2 cases had DCRV as an isolated anomaly, another 2 had the disease associated with VSD, and the remaining 1 had DCRV with right ventricle to left atrium cannulation. Muscular membrane septum type was found in 3 cases, and muscular bundle type in 2.4 cases diagnosed as having DCRV or DCRV with other heart anomalies during operation were treated properly and discharged fully recovered. 1 case died of acute heart insufficiency. Pathologic anatomy and physiology, associated anomalies of DCRV, and some experience with the operative approach were discussed in this article.
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Christiano AM, Rosenbaum LM, Chung-Honet LC, Parente MG, Woodley DT, Pan TC, Zhang RZ, Chu ML, Burgeson RE, Uitto J. The large non-collagenous domain (NC-1) of type VII collagen is amino-terminal and chimeric. Homology to cartilage matrix protein, the type III domains of fibronectin and the A domains of von Willebrand factor. Hum Mol Genet 1992; 1:475-81. [PMID: 1307247 DOI: 10.1093/hmg/1.7.475] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Type VII collagen, the major component of anchoring fibrils, consists of a central collagenous triple-helical segment flanked by non-collagenous domains, NC-1 and NC-2. In this study, we examined the domain organization of human type VII collagen through analysis of deduced amino acid sequences derived from cloned complementary and genomic DNAs, as compared to peptide segments derived from amniotic membrane type VII collagen. The results revealed that the peptide segments derived from the NC-1 domain of type VII collagen could be assigned to the 5' portion of the composite cDNA, indicating that NC-1 resides at the amino terminal end of the molecule. Several sub-domains with homology to adhesive molecules were also identified within NC-1. These protein domains may confer adhesive properties to NC-1, thereby facilitating the binding of type VII collagen to the lamina densa in the cutaneous basement membrane and the anchoring plaques within the dermis.
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Pan TC, Zhang RZ, Mattei MG, Timpl R, Chu ML. Cloning and chromosomal location of human alpha 1(XVI) collagen. Proc Natl Acad Sci U S A 1992; 89:6565-9. [PMID: 1631157 PMCID: PMC49542 DOI: 10.1073/pnas.89.14.6565] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have characterized cDNA clones that encode a newly discovered collagenous polypeptide. A 4-kilobase (kb) cDNA clone was initially isolated by screening a human fibroblast cDNA library with a probe encoding the collagenous domain of the human alpha 3(VI) collagen. Subsequent screening of another fibroblast cDNA library yielded overlapping clones having a total length of 5.4 kb, which contained an open reading frame of 1603 amino acids including a 21-amino acid signal peptide. The predicted polypeptide consists of 10 collagenous domains 15-422 amino acids long, which were interspersed with 11 noncollagenous (NC) domains. Except for a large N-terminal NC11 domain of 312 residues, most of the NC domains were short (11-39 residues) and cysteine-rich. The overall structural arrangement differed significantly from other known collagen chains. Further analysis indicated that the deduced polypeptide exhibited several structural features characteristically seen in members of the fibril-associated collagen, types IX, XII, and XIV. In addition, the cysteine-rich motifs in the NC domains resembled those found in the cuticle collagen of Caenorhabditis elegans. Northern blot analyses showed hybridization of the cDNA to a 5.5-kb mRNA in human fibroblasts and keratinocytes. The gene was localized by in situ hybridization to band p34-35 of human chromosome 1. The data clearly support the conclusion that the cDNA encodes a collagen chain that has not been previously described. We suggest that the cDNA clones encode the alpha 1 chain of type XVI collagen.
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Pan TC. [Surgical treatment of myasthenia gravis and its evaluation]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1992; 30:234-6, 256. [PMID: 1473408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
30 cases of myasthenia gravis (MG) were treated with thymectomy. Before and after operation, peripheral blood lymphocyte subpopulation was determined in 10 cases and acetylcholine receptor antibody titer was determined in 6. The results confirmed the efficacy of thymectomy in treating MG. We suggest that application of hormone for regulating immune function of the body and/or plasma exchange for alleviating symptoms in patients with generalized MG before and after the operation. The results of treatment did not correlate with age, sex, length, and course of the disease. Radical operation, proper anaesthesia and appropriate antibiotics may ensure a smooth operation and high curative effect.
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Saitta B, Wang YM, Renkart L, Zhang RZ, Pan TC, Timpl R, Chu ML. The exon organization of the triple-helical coding regions of the human alpha 1(VI) and alpha 2(VI) collagen genes is highly similar. Genomics 1991; 11:145-53. [PMID: 1765372 DOI: 10.1016/0888-7543(91)90111-q] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The alpha 1(VI) and alpha 2(VI) chains, two of the three constituent chains of type VI collagen, are highly similar in size and domain structure. They are encoded by single-copy genes residing in close proximity on human chromosome 21. To study the evolution of the type VI collagen genes, we have isolated and characterized genomic clones coding for the triple-helical domains of the human alpha 1(VI) and alpha 2(VI) chains, which consist of 336 and 335 amino acid residues, respectively. Nucleotide sequencing indicates that, in both genes, the exons are multiples of 9 bp in length (including 27, 36, 45, 54, 63, and 90 bp) except for those encoding for regions with triple-helical interruptions. In addition, the introns are positioned between complete codons. The most predominant exon size is 63 bp, instead of 54 bp as seen in the fibrillar collagen genes. Of particular interest is the finding that the exon structures of the alpha 1(VI) and alpha 2(VI) genes are almost identical. A significant deviation is that a segment of 30 amino acid residues is encoded by two exons of 54 and 36 bp in the alpha 1(VI) gene, but by a single exon of 90 bp in the alpha 2(VI) gene. The exon arrangement therefore provides further evidence that the two genes have evolved from tandem gene duplication. Furthermore, comparison with the previously reported gene structure of the chick alpha 2(VI) chain indicates that the exon structure for the triple-helical domain of the alpha 2(VI) collagen is strictly conserved between human and chicken.
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Pan TC, Chen QF, Zhang LH, Shen YZ, Xie ZP, Yang MS, Bu BT, Cao XB. Surgical treatment of myasthenia gravis and evaluation of its efficacy. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1991; 11:106-10. [PMID: 1816413 DOI: 10.1007/bf02888097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This paper reports 30 cases of myasthenia gravis (MG) treated by thymectomy from 1965 to 1990 in our hospital. Of all the 30 cases of MG, peripheral blood lymphocyte subpopulation was determined in 10, and anti-acetylcholine receptor antibody titer in 6, before and after operation. The results demonstrated the efficacy of thymectomy against MG. We considered that with application of hormone before and after operation to regulate immune function of the body, and/or with plasma exchange to remiss symptoms, all the patients with generalized MG may be indicated for treatment by thymectomy. Indication of treatment does not depend on age, sex and the course of the disease. But radical operation, proper anesthesia and appropriate use of antibiotics may ensure safety of the operation and its curative effect.
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Chu ML, Zhang RZ, Pan TC, Stokes D, Conway D, Kuo HJ, Glanville R, Mayer U, Mann K, Deutzmann R. Mosaic structure of globular domains in the human type VI collagen alpha 3 chain: similarity to von Willebrand factor, fibronectin, actin, salivary proteins and aprotinin type protease inhibitors. EMBO J 1990; 9:385-93. [PMID: 1689238 PMCID: PMC551678 DOI: 10.1002/j.1460-2075.1990.tb08122.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human collagen alpha 3(VI) chain mRNA (approximately 10 kb) was cloned and shown by sequence analysis to encode a 25 residue signal peptide, a large N-terminal globule (1804 residues), a central triple helical segment (336 residues) and a C-terminal globule (803 residues). Some of the sequence was confirmed by Edman degradation of peptides. The N-terminal globular segment consists of nine consecutive 200 residue repeats (N1 to N9) showing internal homology and also significant identity (17-25%) to the A domains of von Willebrand Factor and similar domains present in some other proteins. Deletions were found in the N3 and N9 domains of several cDNA clones suggesting variation of these structures by alternative splicing. The C-terminal globule starts immediately after the triple helical segment with two domains C1 (184 residues) and C2 (248 residues) being similar to the N domains. They are followed by a proline rich, repetitive segment C3 of 122 residues, with similarity to some salivary proteins, and domain C4 (89 residues), which is similar to the type III repeats present in fibronectin and tenascin. The most C-terminal domain C5 (70 residues) shows 40-50% identity to a variety of serine protease inhibitors of the Kunitz type. The whole sequence contains 29 cysteines which are mainly clustered in short segments connecting domains N1, C1, C2 and the triple helix, and in the inhibitor domain. Five putative Arg-Gly-Asp cell-binding sequences are exclusively localized in the triple helical segment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Chu ML, Pan TC, Conway D, Saitta B, Stokes D, Kuo HJ, Glanville RW, Timpl R, Mann K, Deutzmann R. The structure of type VI collagen. Ann N Y Acad Sci 1990; 580:55-63. [PMID: 2337306 DOI: 10.1111/j.1749-6632.1990.tb17917.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Chu ML, Pan TC, Conway D, Kuo HJ, Glanville RW, Timpl R, Mann K, Deutzmann R. Sequence analysis of alpha 1(VI) and alpha 2(VI) chains of human type VI collagen reveals internal triplication of globular domains similar to the A domains of von Willebrand factor and two alpha 2(VI) chain variants that differ in the carboxy terminus. EMBO J 1989; 8:1939-46. [PMID: 2551668 PMCID: PMC401054 DOI: 10.1002/j.1460-2075.1989.tb03598.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Amino acid sequences of human collagen alpha 1(VI) and alpha 2(VI) chains were completed by cDNA sequencing and Edman degradation demonstrating that the mature polypeptides contain 1009 and 998 amino acid residues respectively. In addition, they contain small signal peptide sequences. Both chains show 31% identity in the N-terminal (approximately 235 residues) and C-terminal (approximately 430 residues) globular domains which are connected by a triple helical segment (335-336 residues). Internal alignment of the globular sequences indicates a repetitive 200-residue structure (15-23% identity) occurring three times (N1, C1, C2) in each chain. These repeating subdomains are connected to each other and to the triple helix by short (15-30 residues) cysteine-rich segments. The globular domains possess several N-glycosylation sites but no cell-binding RGD sequences, which are exclusively found in the triple helical segment. Sequencing of alpha 2(VI) cDNA clones revealed two variant chains with a distinct C2 subdomain and 3' non-coding region. The repetitive segments C1, C2 and, to a lesser extent, N1 show significant identity (15-18%) to the collagen-binding A domains of von Willebrand factor (vWF) and they are also similar to some integrin receptors, complement components and a cartilage matrix protein. Since the globular domains of collagen VI come into close contact with triple helical segments during the formation of tissue microfibrils it suggests that the globular domains bind to collagenous structures in a manner similar to the binding of vWF to collagen I.
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Mann K, Deutzmann R, Aumailley M, Timpl R, Raimondi L, Yamada Y, Pan TC, Conway D, Chu ML. Amino acid sequence of mouse nidogen, a multidomain basement membrane protein with binding activity for laminin, collagen IV and cells. EMBO J 1989; 8:65-72. [PMID: 2496973 PMCID: PMC400773 DOI: 10.1002/j.1460-2075.1989.tb03349.x] [Citation(s) in RCA: 167] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The whole amino acid sequence of nidogen was deduced from cDNA clones isolated from expression libraries and confirmed to approximately 50% by Edman degradation of peptides. The protein consists of some 1217 amino acid residues and a 28-residue signal peptide. The data support a previously proposed dumb-bell model of nidogen by demonstrating a large N-terminal globular domain (641 residues), five EGF-like repeats constituting the rod-like domain (248 residues) and a smaller C-terminal globule (328 residues). Two more EGF-like repeats interrupt the N-terminal and terminate the C-terminal sequences. Weak sequence homologies (25%) were detected between some regions of nidogen, the LDL receptor, thyroglobulin and the EGF precursor. Nidogen contains two consensus sequences for tyrosine sulfation and for asparagine beta-hydroxylation, two N-linked carbohydrate acceptor sites and, within one of the EGF-like repeats an Arg-Gly-Asp sequence. The latter was shown to be functional in cell attachment to nidogen. Binding sites for laminin and collagen IV are present on the C-terminal globule but not yet precisely localized.
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Chu ML, Conway D, Pan TC, Baldwin C, Mann K, Deutzmann R, Timpl R. Amino acid sequence of the triple-helical domain of human collagen type VI. J Biol Chem 1988; 263:18601-6. [PMID: 3198591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The complete amino acid sequence of the triple-helical domain of human collagen VI was deduced from sequences of appropriate cDNA clones and confirmed to about 50% by Edman degradation of tryptic peptides. This domain consists of three different peptide segments containing some 335-336 amino acid residues originating from central portions of the alpha 1 (VI), alpha 2(VI), and alpha 3(VI) chains, respectively. Sequence identity in the X/Y positions of the Gly-X-Y repeats is rather low (10-15%) between the chains. Peculiar features of these sequences include 3 cysteine residues about 50 (alpha 3(VI)) and 89 (alpha 1(VI), alpha 2(VI)) residues away from the N-terminus and several Gly-X-Y interruptions clustered in the C-terminal two-thirds of the triple helix. These structures are presumably required for cross-linking collagen VI oligomers and for super-coiling of triple helices in the dimers. Other features include 11 Arg-Gly-Asp sequences, some of which are likely to be used as cell-binding sites, and four Asn-X-Thr sequences, allowing N-linked glycosylation along the triple helix. Junctional areas close to the helix contain short, cysteine-rich segments which may seal the triple-helical domain through disulfide bond formation, endowing it with high stability. These features, together with a low sequence homology to fiber-forming and basement-membrane collagens, document the unique character of collagen VI, whose triple helix is specifically adjusted for forming microfibrils in tissues.
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Chu ML, Conway D, Pan TC, Baldwin C, Mann K, Deutzmann R, Timpl R. Amino acid sequence of the triple-helical domain of human collagen type VI. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37327-7] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Chao YS, Ding XH, Dai PH, Wu TJ, Pan TC, Hao QL, Yamin TT. Identification of an enhancer-like element in the 5' flanking region of the rat apolipoprotein A-I gene. Nucleic Acids Res 1988; 16:7061-70. [PMID: 3136438 PMCID: PMC338351 DOI: 10.1093/nar/16.14.7061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In order to study the expression of the apolipoprotein (apo) A-I gene, we have isolated and characterized the structural gene encoding rat apo A-I. The 5' flanking sequence of the apo A-I gene was placed upstream of the coding sequence of the bacterial chloramphenicol acetyl transferase (CAT) gene, such that the expression of CAT activity in cultured cells is under the control of the promoter and regulatory sequences of the rat apo A-I gene. By transient transfection, nucleotide deletion and substitution methods, it was demonstrated that the nucleotide sequences between -464 and -148 upstream from the start of transcription of the rat apo A-I gene are required for the expression of this gene in Hep G2 cells and that these sequences function with an enhancer-like activity.
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Pan TC. [Determination of mercury and arsenic concentrations in urine by cold vapor and hydride atomic absorption spectrophotometry]. GAOXIONG YI XUE KE XUE ZA ZHI = THE KAOHSIUNG JOURNAL OF MEDICAL SCIENCES 1988; 4:123-31. [PMID: 3283371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Pan TC, Hao QL, Yamin TT, Dai PH, Chen BS, Chen SL, Kroon PA, Chao YS. Rabbit apolipoprotein A-I mRNA and gene. Evidence that rabbit apolipoprotein A-I is synthesized in the intestine but not in the liver. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 170:99-104. [PMID: 3121329 DOI: 10.1111/j.1432-1033.1987.tb13672.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to study the tissue-specific expression of rabbit apolipoprotein (apo) A-I, a 923-base-pair clone, pRBA-502, complementary to rabbit apo A-I mRNA was identified from a rabbit intestinal cDNA library by hybrid-select translation and immunoprecipitation methods. Northern blot and dot-blot hybridization, utilizing 32P-labeled pRBA-502, revealed that the rabbit apo A-I gene is expressed in the intestine, not in the liver and that rabbit apo A-I mRNA is about 950 nucleotides in length. The entire nucleotide sequence of pRBA-502 has been determined and the complete amino acid sequence of the corresponding apo A-I has been deduced. The mRNA codes for a protein comprising 265 amino acids. Amino acids 1-18 and 19-24 of the primary translation product represent the presegment and prosegment, respectively, of apo A-I. Matured rabbit apo A-I contains 241 amino acids and has a molecular mass of 27612 Da. Using pRBA-502 as a probe, a 15.5-kb genomic fragment, which contains the entire apo A-I gene, was isolated from a rabbit liver genomic library. Sequence analysis of the gene shows that the 200 base pairs of the 5' upstream flanking region of the rabbit and human apo A-I genes showed 78% sequence homology. Like the human apo A-I gene, the rabbit apo A-I gene is interrupted by three intervening sequences. Except for two nucleotides in the fourth exon, the coding sequence of the rabbit liver apo A-I gene is identical to that of pRBA-502. Our data showed that the lack of expression of apo A-I gene in rabbit liver is not due to the alternation of rabbit liver apo A-I gene sequence and suggest that the expression of apo A-I gene in rabbit liver is regulated by a trans-acting regulating element(s).
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Hao QL, Yamin TT, Pan TC, Chen SL, Chen BS, Kroon PA, Chao YS. Isolation and characterization of a full-length rabbit apolipoprotein E cDNA. Atherosclerosis 1987; 66:125-30. [PMID: 3632744 DOI: 10.1016/0021-9150(87)90187-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In order to study the primary structure of rabbit apolipoprotein (apo) E and the regulation of levels of liver apo E mRNA by dietary cholesterol, we have cloned and sequenced a full length rabbit apo E cDNA. DNA sequence analyses suggests that rabbit apo E is synthesized with an additional 18 amino acids as the prepeptide. The mature rabbit apo E contains 293 amino acids with a calculated molecular weight of 33,528. It has a 76% amino acid sequence homology with human apo E. Northern blot analyses showed that rabbit apo E mRNA is about 1200 nucleotides in length. Using mRNA dot blot analyses, we found that dietary cholesterol has no effect on the level of apo E mRNA in rabbit liver. We conclude that the elevated levels of plasma apo E in rabbits fed a cholesterol-rich diet is not a result of an increase of levels of apo E mRNA in the liver.
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Lin SM, Tsai JL, Pan TC. [Normal reference values of serum zinc in adults: a study by flame atomic absorption spectrophotometry]. GAOXIONG YI XUE KE XUE ZA ZHI = THE KAOHSIUNG JOURNAL OF MEDICAL SCIENCES 1987; 3:128-32. [PMID: 3482275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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