EurekaMag.com logo
+ Site Statistics
References:
48,253,228
Abstracts:
22,798,842
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Electrophoretically slow and fast forms of the alpha 2 macro globulin molecule


, : Electrophoretically slow and fast forms of the alpha 2 macro globulin molecule. Biochemical Journal 181(2): 401-418

.alpha.2-Macroglobulin (.alpha.2M) was isolated from human plasma by a 4-step procedure: poly(ethylene glycol) fractionation, gel chromatography, euglobulin precipitation and immunoadsorption. No contaminants were detected in the final preparations by electrophoresis or immunoprecipitation. The protein ran as a single slow band in gel electrophoresis and was designated S-.alpha.2M. S-.alpha.2M bound about 2 mol of trypsin/mol. Treatment of S-.alpha.2M with a proteinase or ammonium salts produced a form of the molecule more mobile in electrophoresis and lacking proteinase-binding activity (F-.alpha.2M). Electrophoretic mobility of the F-.alpha.2M resulting from reaction with NH4+ salts was identical with that of proteinase complexes. Change in electrophoretic mobility of the .alpha.2M was attributed to a conformational change, but there was no evidence of a change in pI or Stokes radius. Electrophoresis of S-.alpha.2M in the presence of sodium dodecyl sulfate [SDS] gave results consistent with the view that the .alpha.2M molecule is a tetramer of identical subunits, assembled as a non-covalent pair of disulfide-linked dimers. Some subunits seemed to be nicked into 2/3 length and 1/3 length chains. This was not apparent with F-.alpha.2M produced by ammonium salts. F-.alpha.2M produced by trypsin showed 2 new bands attributable to cleavage of the subunit polypeptide chain near the middle. Immunoassays of F-.alpha.2M gave rockets 12-29% lower than those with S-.alpha.2M. The nature of interactions between subunits in S-.alpha.2M and F-.alpha.2M was investigated by treating each form with glutaraldehyde before electrophoresis in the presence of SDS. A much greater degree of cross-linking was observed with the F-.alpha.2M, indicating that subunits interact most closely in this form of the molecule. Exposure of S-.alpha.2M to 3 M-urea or pH 3 resulted in dissociation to disulfide-bonded half-molecules; these did not show proteinase-binding activity characteristic of the intact .alpha.2M. F-.alpha.2M was less easily dissociated than was S-.alpha.2M. S-.alpha.2M was readily dissociated to the quarter-subunits by mild reduction, with the formation of 3-4 new thiol groups/subunit. Intact reactive .alpha.2M could then be regenerated in high yield by reoxidation of the subunits. F-.alpha.2M formed by reaction with a proteinase or ammonium salts was not dissociated under the same conditions, although the interchain disulphide bonds were reduced. If thiol groups of the quarter-subunits of S-.alpha.2M were blocked by carboxymethylation, oxidative reassociation did not occur. Treatment of these subunits with methylammonium salts or a proteinase caused the reassembly of half-molecules and intact (F-) tetramers. F-.alpha.2M does not have the properties of a denatured form of the protein. One interpretation of the difference in properties between the S- and F-forms is that the S-form is a planar tetramer, whereas the F-form is pseudotetrahedral. Results are considered in relation to the trap hypothesis for the reaction of .alpha.2M with proteinases.

(PDF 0-2 workdays service)

Order PDF Full Text

Close
Close

Click here to order any other PDF Full Text


Accession: 005349221

PDF Full Text: Submit


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Other references

Bruggencate G.T.; Engberg I., 1971: Iontophoretic studies in deiters nucleus of the inhibitory actions of gamma amino butyric acid and related amino acids and the interactions of strychnine and picro toxin. Brain Research 25(3): 431-448

Sioud, M.; Kjeldsen-Kragh, J.; Quayle, A. J.; Wiker, H. G.; Sorskaar, D.; Natvig, J. B.; Forre, O., 1991: Immune responses to 18.6 and 30 kda mycobacterial antigens in rheumatoid patients and vbeta usage by specific synovial t cell lines and fresh t cells. We have investigated both the humoral and the cellular immune responses of patients with juvenile rheumatoid arthritis (JRA) and rheumatoid arthritis (RA) to mycobacterial antigens. The JRA group was not Bacillus Calmettee Guerin (BCG) vaccinated...

Schnagl, Rd; Holmes, Ih, 1978: Coronavirus like particles in stools form dogs, from some country areas of Australia. Veterinary record: 7, 102 (24) 528-529

Bowers A.J., 1986: Reversals delinquency and disruption. The tendency to operate in the telic rather than the paratelic state was examined in three groups of adolescent boys. Those in the first group had a record of criminal behaviour, the second group consisted of subjects whose school behaviour was re...

Osofsky, Joy D.; Wewers, Sarah; Hann, Della M.; Fick, Ana C., 1993: Chronic community violence What is happening to our children?. Psychiatry (New York) 56(1): 36-45

Kitawaki, Jo; Kiyomizu, Miyo; Obayashi, Hiroshi; Ohta, Mitsuhiro; Ishihara, Hiroaki; Hasegawa, Goji; Nakamura, Naoto; Yoshikawa, Toshikazu; Honjo, Hideo, 2006: Synergistic effect of interleukin-6 promoter (IL6-634C/G) and intercellular adhesion molecule-1 (ICAM-1 469K/E) gene polymorphisms on the risk of endometriosis in Japanese women. Problem Endometriosis is an immune-related, chronic inflammatory disease with a polygenic predisposition. The aim of this study was to investigate whether the interleukin-6 (IL-6) gene promoter region polymorphism (-634C/G) and the intercellular a...

Fang, Fang; Liu, Gengtao, 2007: A novel cyclic squamosamide analogue compound FLZ improves memory impairment in artificial senescence mice induced by chronic injection of D-galactose and NaNO2. The aim of the present study was to access the protective effect of a novel synthesized squamosamide cyclic analogue, compound FLZ, on memory impairment in artificially senescent mice induced by chronic injection of D-galactose and sodium nitrite...

Kamelhar, D. L.; Steele, J. M-Jr ; Schacht, R. G.; Lowenstein, J.; Naftchi, N. E., 1978: Plasma renin and serum dopamine beta hydroxylase during orthostatic hypotension in quadriplegic man. To determine whether orthostatic hypotension in patients with cervical spinal cord lesions is the result of impaired sympathetic nerve response and/or impaired renin release, serum dopamine-.beta.-hydroxylase (D.beta.H) activity and plasma renin a...

Vijayambika V.; Cicilykutty A.K.; Balasubramanian N.K.; John P.A., 1979: Geographic variation in the intensity of infestation of the fish mite lardoglyphus konoi in kerala south india. Counts of L. konoi (Sasa et Asanuma) on samples of dried fish collected from warehouses along the southwest coast of Kerala (India) during 1975, revealed a striking disparity in the intensity of infestation among the different localities of collec...

Shinohara M.; Urabe T.; Ohmi S.; Umakoshi Kodo; Kuwahara S., 1988: Shallow reflection seismic profiling across the fissure of Izu-Oshima. Kasan = Bulletin of the Volcanological Society of Japan 33(3): 226-227