The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles
| ISSN: |
0005-2795
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|---|---|
| Source: |
Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
|
| Topics: |
Biology
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| Type of Medium: |
Electronic Resource
|
| URL: |
| _version_ | 1798292385331937280 |
|---|---|
| autor | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. |
| autorsonst | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. |
| book_url | http://linkinghub.elsevier.com/retrieve/pii/0005-2795(77)90258-6 |
| datenlieferant | nat_lic_papers |
| fussnote | In these studies an α"1-an α"2-macroglobulin were isolated from rat serum. The α"2 protein had all the opsonic activity, promoting phagocytosis of various colloidal particles by rat liver slices. The opsonin was stable in the lyophilized form or in solution kept in ice. The opsonic activity was lost slowly at 37 ^oC at all pH values between 3.5 and 9.5. The activity increased when the protein was preincubated at 37 ^oC for 20 min. Measurement of optical rotatory dispersion suggested that no major change of conformation occurred when the temperature was raised to 37 ^oC. The protein dissociated, however, into two subunits at 37 ^oC. The activity was lost when the protein was incubated at 60 ^oC. The opsonin contained 6.5% carbohydrate comprised of hexosamine, hexose and sialic acid. Neuraminidase treatment released all the sialic acid without affecting the opsonic activity. Trypsin treatment inactivated the protein after prolonged incubation.The α"2-opsonic promoted phagocytosis of the test lipid emulsion of the reticuloendothelial system, colloidal gold and sulfur. It also stimulated the uptake of membrane fragments from heart, liver, skeletal muscle, skin and cancer cells. It is suggested that one of the most important physiological roles of the opsonin is to promote clearance of tissue debris produced under various adverse conditions. The uptake of two species of bacteria was also enhanced by the protein.The opsonin did not bind trypsin, all the trypsin binding activity was associated with the α"1-macroglobulin fraction. In this respect the α"2-opsonin is not related to the α"2-macroglobulin of human serum or to the α"2 acute phase macroglobulin of rat serum, both of which are known to bind proteolytic enzymes.Furthermore, an antiserum prepared against human α"2-macroglobulin did not show a precipitin line when tested against the opsonin even though it reacted weakly with rat serum indicating the presence of a cross-reacting antigen in rat serum. These data showed that the human α"2-macroglobulin and the rat α"2-opsonin are not related antigenically.The uptake of colloids in vitro required heparin as an obligatory cofactor, 5 units of heparin were optimal. Polyethylene sulfonate could replace heparin but chondroitin sulfate A and C were without effects. |
| hauptsatz | hsatz_simple |
| identnr | NLZ186073798 |
| issn | 0005-2795 |
| journal_name | BBA - Protein Structure |
| materialart | 1 |
| package_name | Elsevier |
| publikationsort | Amsterdam |
| publisher | Elsevier |
| reference | 493 (1977), S. 37-54 |
| search_space | articles |
| shingle_author_1 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. |
| shingle_author_2 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. |
| shingle_author_3 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. |
| shingle_author_4 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. |
| shingle_catch_all_1 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles 0005-2795 00052795 Elsevier |
| shingle_catch_all_2 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles 0005-2795 00052795 Elsevier |
| shingle_catch_all_3 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles 0005-2795 00052795 Elsevier |
| shingle_catch_all_4 | Molnar, J. McLain, S. Allen, C. Laga, H. Gara, A. Gelder, F. The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles 0005-2795 00052795 Elsevier |
| shingle_title_1 | The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles |
| shingle_title_2 | The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles |
| shingle_title_3 | The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles |
| shingle_title_4 | The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles |
| sigel_instance_filter | dkfz geomar wilbert ipn albert fhp |
| source_archive | Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 |
| timestamp | 2024-05-06T08:47:40.767Z |
| titel | The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles |
| titel_suche | The role of an α"2-macroglobulin of rat serum in the phagocytosis of colloidal particles In these studies an α"1-an α"2-macroglobulin were isolated from rat serum. The α"2 protein had all the opsonic activity, promoting phagocytosis of various colloidal particles by rat liver slices. The opsonin was stable in the lyophilized form or in solution kept in ice. The opsonic activity was lost slowly at 37 ^oC at all pH values between 3.5 and 9.5. The activity increased when the protein was preincubated at 37 ^oC for 20 min. Measurement of optical rotatory dispersion suggested that no major change of conformation occurred when the temperature was raised to 37 ^oC. The protein dissociated, however, into two subunits at 37 ^oC. The activity was lost when the protein was incubated at 60 ^oC. The opsonin contained 6.5% carbohydrate comprised of hexosamine, hexose and sialic acid. Neuraminidase treatment released all the sialic acid without affecting the opsonic activity. Trypsin treatment inactivated the protein after prolonged incubation.The α"2-opsonic promoted phagocytosis of the test lipid emulsion of the reticuloendothelial system, colloidal gold and sulfur. It also stimulated the uptake of membrane fragments from heart, liver, skeletal muscle, skin and cancer cells. It is suggested that one of the most important physiological roles of the opsonin is to promote clearance of tissue debris produced under various adverse conditions. The uptake of two species of bacteria was also enhanced by the protein.The opsonin did not bind trypsin, all the trypsin binding activity was associated with the α"1-macroglobulin fraction. In this respect the α"2-opsonin is not related to the α"2-macroglobulin of human serum or to the α"2 acute phase macroglobulin of rat serum, both of which are known to bind proteolytic enzymes.Furthermore, an antiserum prepared against human α"2-macroglobulin did not show a precipitin line when tested against the opsonin even though it reacted weakly with rat serum indicating the presence of a cross-reacting antigen in rat serum. These data showed that the human α"2-macroglobulin and the rat α"2-opsonin are not related antigenically.The uptake of colloids in vitro required heparin as an obligatory cofactor, 5 units of heparin were optimal. Polyethylene sulfonate could replace heparin but chondroitin sulfate A and C were without effects. |
| topic | W |
| uid | nat_lic_papers_NLZ186073798 |