PMID- 1370602
OWN - NLM
STAT- MEDLINE
DCOM- 19920218
LR  - 20190628
IS  - 0003-9861 (Print)
IS  - 0003-9861 (Linking)
VI  - 292
IP  - 2
DP  - 1992 Feb 1
TI  - Binding of transforming growth factor-beta 1 to immobilized human alpha 
      2-macroglobulin.
PG  - 487-92
AB  - Native alpha 2-macroglobulin (alpha 2M) and alpha 2M-methylamine were immobilized 
      in 96-well microtiter plates. 125I-labeled transforming growth factor-beta 1 
      (TGF-beta 1) bound to both alpha 2M variants; however, greater binding was 
      observed with alpha 2M-methylamine. Binding of 125I-TGF-beta 1 (0.2 nM) to 
      immobilized alpha 2M-methylamine was inhibited by nonradiolabeled TGF-beta 1 (up 
      to 74% with 0.4 microM TGF-beta 1). Approximately 10% of the TGF-beta 1-alpha 
      2M-methylamine complex was covalent. Treatment of alpha 2M-methylamine with 
      iodoacetamide prior to immobilization completely eliminated covalent TGF-beta 1 
      binding; the total amount of 125I-TGF-beta 1-alpha 2M-methylamine complex 
      detected was unchanged. The binding of 125I-TGF-beta 1 to immobilized alpha 
      2M-methylamine was not significantly inhibited by increasing the ionic strength 
      to 1.0 M. Binding and complex dissociation were also unaffected by changes in pH 
      within the range 6.9-8.9. Acidic pH dramatically decreased binding and promoted 
      complex dissociation; no binding of 125I-TGF-beta 1 to immobilized alpha 
      2M-methylamine was detected at pH 3.5. The interaction of TGF-beta 1 with 
      immobilized alpha 2M-methylamine was not significantly changed by 1.0 mM EDTA or 
      1.0 mM CaCl2. ZnCl2 (1.0 mM) completely eliminated binding. This result was not 
      due to TGF-beta 1 precipitation or aggregation. Inhibition of 125I-TGF-beta 1 
      binding to alpha 2M-methylamine was 50% complete (IC50) with 30 microM ZnCl2. 
      Native alpha 2M, thrombospondin, and alpha 2M-methylamine (in solution) decreased 
      binding of 125I-TGF-beta 1 to immobilized alpha 2M-methylamine. The IC50 values 
      for these three proteins were 520, 160, and 79 nM, respectively. The TGF-beta 
      1-binding activity of native alpha 2M may have reflected, at least in part, 
      trace-contamination with alpha 2M-proteinase complex.
FAU - Webb, D J
AU  - Webb DJ
AD  - Department of Pathology, University of Virginia Health Sciences Center, 
      Charlottesville 22908.
FAU - Crookston, K P
AU  - Crookston KP
FAU - Hall, S W
AU  - Hall SW
FAU - Gonias, S L
AU  - Gonias SL
LA  - eng
GR  - GM 07267/GM/NIGMS NIH HHS/United States
GR  - HL-02272/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Arch Biochem Biophys
JT  - Archives of biochemistry and biophysics
JID - 0372430
RN  - 0 (Platelet Membrane Glycoproteins)
RN  - 0 (Thrombospondins)
RN  - 0 (Transforming Growth Factor beta)
RN  - 0 (alpha-Macroglobulins)
SB  - IM
MH  - Binding, Competitive
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Kinetics
MH  - Platelet Membrane Glycoproteins/metabolism
MH  - Protein Binding
MH  - Thrombospondins
MH  - Transforming Growth Factor beta/*metabolism
MH  - alpha-Macroglobulins/*metabolism
EDAT- 1992/02/01 00:00
MHDA- 1992/02/01 00:01
CRDT- 1992/02/01 00:00
PHST- 1992/02/01 00:00 [pubmed]
PHST- 1992/02/01 00:01 [medline]
PHST- 1992/02/01 00:00 [entrez]
AID - 0003-9861(92)90020-W [pii]
AID - 10.1016/0003-9861(92)90020-w [doi]
PST - ppublish
SO  - Arch Biochem Biophys. 1992 Feb 1;292(2):487-92. doi: 
      10.1016/0003-9861(92)90020-w.