TY - JOUR
T1 - Studies of radioiodinated fibrinogen I. Physicochemical properties of the ICl, chloramine-T, and electrolytic reaction products
AU - Krohn, Kenneth
AU - Sherman, Laurence
AU - Welch, Michael
N1 - Funding Information:
The authors wish to thank their colleagues in the Washington University Thrombosis Center for helpful discussions and the National Heart and Lung Institute for financial assistance (S.C.O.R. Thrombosis Center Grant No. I PI 7 HE 14147-Ol ). Especially significant was the contribution of Professor E. James Potchen and the assistance of Judy Metzger, Sylvia Harwig and Roger Secker-Walker.
PY - 1972/12/28
Y1 - 1972/12/28
N2 - The rate of catabolism of fibrinogen is known to be increased by extensive iodination. (MacFarlane, A.S., (1963) J. Clin. Invest. 42, 346-361) Clottability measurements are, however, insensitive to this biological damage. (Regoeczi, E., (1971) J. Nucl. Biol. Med. 15, 37-41). We have used gel permeation chromatography in an attempt to understand the chemical modifications of the protein that underlie this alteration in biological activity. In a comparative study of 125I-labelled fibrinogen labelled by the ICl, chloramine-T, and electrolytic methods, we have found that product 125I-labelled fibrinogen is formed with a molecular weight significantly greater than that of normal fibrinogen. The chloramine-T method gives the highest degree of aggregation and the ICl method gives a product whose molecular weight profile most clearly resembles that of authentic fibrinogen. All of the products are hydrolyzed at similar rates in saline (30 ± 3% in the first 24 h) and in plasma or albumin (2.0 ± 0.5% per day). Some chloramine-T preparations have been noted to be more rapidly hydrolyzed in plasma following a two-day induction period. The rate of breakdown is slower in polyethylene containers than in glass. Our results suggest that ICl preparations of 125I-labelled fibrinogen show the least alteration in chemical properties and may therefore be the best for use in in vivo tracer studies involving radioiodinated fibrinogen.
AB - The rate of catabolism of fibrinogen is known to be increased by extensive iodination. (MacFarlane, A.S., (1963) J. Clin. Invest. 42, 346-361) Clottability measurements are, however, insensitive to this biological damage. (Regoeczi, E., (1971) J. Nucl. Biol. Med. 15, 37-41). We have used gel permeation chromatography in an attempt to understand the chemical modifications of the protein that underlie this alteration in biological activity. In a comparative study of 125I-labelled fibrinogen labelled by the ICl, chloramine-T, and electrolytic methods, we have found that product 125I-labelled fibrinogen is formed with a molecular weight significantly greater than that of normal fibrinogen. The chloramine-T method gives the highest degree of aggregation and the ICl method gives a product whose molecular weight profile most clearly resembles that of authentic fibrinogen. All of the products are hydrolyzed at similar rates in saline (30 ± 3% in the first 24 h) and in plasma or albumin (2.0 ± 0.5% per day). Some chloramine-T preparations have been noted to be more rapidly hydrolyzed in plasma following a two-day induction period. The rate of breakdown is slower in polyethylene containers than in glass. Our results suggest that ICl preparations of 125I-labelled fibrinogen show the least alteration in chemical properties and may therefore be the best for use in in vivo tracer studies involving radioiodinated fibrinogen.
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U2 - 10.1016/0005-2795(72)90327-3
DO - 10.1016/0005-2795(72)90327-3
M3 - Article
C2 - 4659649
AN - SCOPUS:0015527821
SN - 0005-2795
VL - 285
SP - 404
EP - 413
JO - BBA - Protein Structure
JF - BBA - Protein Structure
IS - 2
ER -