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DOMAIN STRUCTURE OF
ß-THROMBOGLOBULIN The domain structure of the
β-thromboglobulin monomer
is represented. The β-thromboglobulin monomer is an 8,800
molecular weight peptide which is derived via NH2-terminal proteolysis of a
precursor molecule LAPF-4 (low affinity platelet factor-4). Although the
COOH-terminal
domain of β-thromboglobulin is characterized by a clustering of
basic lysine residues, the affinity of b-thromboglobulin for
heparin is significantly weaker than that of platelet factor-4. In its native state,
β-thromboglobulin is a homotetramer consisting of four, identical,
noncovalently-associated peptide chains.
PURCHASING
AND PRODUCT INFORMATION
|
Catalog
Number
HBTG-0210 |
Description
Human β-Thromboglobulin |
Size
100
µg
|
Formulation
25
mM Hepes, 150 mM NaCl, pH 7.4
|
|
Storage
-80oC |
Purity
>95%
by SDS-PAGE |
Activity
Determination
N/A |
Shelf
Life (properly stored)
12
months |
 |
Sample Gel
Information:
Gel:
Novex 4-12% Bis-Tris
Load:
Human Beta Thromboglobulin, 1 µg per lane
Buffer:
MES
Standard:
SeeBluePlus 2; Myosin (188 kDa), Phosphorylase B (98 kDa), BSA (62
kDa), Glutamic Dehydrogenase (49 kDa), Alcohol Dehydrogenase (38 kDa),
Carbonic Anhydrase (28 kDa), Myoglobin Red (17 kDa), Lysozyme (14
kDa), Aprotinin (6 kDa), Insulin, B chain (3 kDa). |
|
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Pricing |
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inquiry |
SAMPLE
DATA SHEET |
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NOW! |
Overview
of β-Thromboglobulin
β-thromboglobulin (b-TG), is a low molecular weight, heparin-binding, platelet-derived protein (1). It is similar to
platelet factor-4 (PF-4) in that it is localized within the platelet
alpha-granule at levels reported to range from 8.1-24.2 µg per 109 platelets (2,3). The relative concentration of
β-TG in platelets exceeds that of plasma by 260,000-fold (4) making
β-TG a convenient marker of platelet activation. Structurally,
β-TG is analogous to PF-4 in that, in its native state,
β-TG is a tetramer (1) consisting of four identical 8800 molecular weight peptide chains (5). In contrast to PF-4,
β-TG exhibits a lower affinity for heparin and also exists as a larger molecular weight species known as "low affinity PF-4" (LAPF-4) (2).
β-TG is derived from the proteolytic removal of four
NH2-terminal amino acid residues from a LAPF-4 (6,7). Immunological screening of partially fractionated supernatant from activated platelets revealed a highly basic form of
β-TG distinct from LAPF-4 (7). This basic
β-TG species, termed platelet basic protein (PBP), was subsequently isolated (8) and later concluded from immunological, peptide sequencing, and proteolytic processing studies to be a higher molecular weight precursor form of both LAPF-4 and
β-TG (9,10).
The physiological function of β-TG is not known. While early studies suggested that the precursor forms of
β-TG were mitogenic for mouse fibroblasts (8,11), it was later concluded that this activity was due to growth factor contamination (10).
β-TG has also been reported to inhibit
prostacyclin-I2 production by endothelial cells (12), however, the relevance of this effect has been called into question (13,14). The chemotactic activity of platelet
alpha-granule proteins for human fibroblasts has been attributed to both PF-4 and
β-TG (15).
Human β-TG is prepared from the supernatant of activated platelets by heparin-agarose affinity chromatography and gel filtration (1,2). The purified protein is supplied in 25 mM Hepes, 150 mM NaCl pH 7.4 and should be stored at
-80°C. Purity is assessed by SDS-PAGE analysis.
Properties of
β-Thromboglobulin
| Localization: |
platelet alpha-granule (3) |
| Mode of action: |
heparin-binding protein: Plasma concentration used as a marker of platelet activation |
| Molecular weight: |
35,800 (1) |
| Extinction coefficient: |
|
| Structure: |
homotetramer (monomer, Mr~8800) (5) |
*calculated based upon amino acid sequence and molecular weight
PURCHASING
AND PRODUCT INFORMATION
|
Catalog
Number
HBTG-0210 |
Description
Human β-Thromboglobulin |
Size
100
µg
|
Formulation
25
mM Hepes, 150 mM NaCl, pH 7.4
|
|
Storage
-80oC |
Purity
>95%
by SDS-PAGE |
Activity
Determination
N/A |
Shelf
Life (properly stored)
12
months |
|
U.S.
Pricing |
Product
inquiry |
SAMPLE
DATA SHEET |
ORDER
NOW! |
References
1. Moore, S., et al., Biochim. Biophys. Acta, 379, 360 (1975).
2. Rucinski, B., et al., Blood, 53, 47 (1979).
3. Kaplan, K.L., et al., Blood, 53, 604 (1979).
4. George, J.N., Blood, 76, 859 (1990).
5. Begg, S., et al., Biochemistry, 17, 1739 (1978).
6. Holt, J.C. and Niewiarowski, S., Biochim. Biophys. Acta, 632, 284 (1980).
7. Niewiarowski, S., et al., Blood, 55, 453 (1980).
8. Paul, D., et al., Proc. Natl. Acad. Sci. USA, 77, 5914 (1980).
9. Varma, K.G., et al., Biochim. Biophys. Acta, 701, 7 (1982).
10. Holt, J.C., et al., Biochemistry, 25, 1988 (1986).
11. Niewiarowski, S. and Paul, D., in Platelets in Biology and Pathology, Vol. 2, pp. 91-106, (Gordon, J.L. ed.) Elsevier/North-Holland Biomedical Press (1981).
12. Hope, W., et al., Nature, 282, 210 (1979).
13. Ager, A. and Gordon, J.L., Thromb. Res., 24, 95 (1981).
14. Poggi, A. et al., Proc. Soc. Exp. Biol. Med., 172, 543 (1983).
15. Senior, R.M., et al., J. Cell. Biol., 96, 382 (1983).
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