Laminin-121--recombinant expression and interactions with integrins.
Laminin-121, previously referred as to laminin-3, was expressed recombinantly in human embryonic kidney (HEK) 293 cells by triple transfection of full-length cDNAs encoding mouse laminin α1, β2 and γ1 chains. The recombinant laminin-121 was purified using Heparin-Sepharose followed by molecular sieve chromatography and shown to be correctly folded by electron microscopy and circular dichroism (CD). The CD spectra of recombinant laminin-121 were very similar to those of laminin-111 isolated from Engelbreth-Holm-Swarm tumor (EHS-laminin) but its T(m) value was smaller than EHS-laminin and recombinant lamnin-111 suggesting that the replacement of the β chain reduced the stability of the coiled-coil structure of laminin-121. Its binding to integrins was compared with EHS-laminin, laminin-3A32 purified from murine epidermal cell line and recombinantly expressed laminins-111, -211 and -221. Laminin-121 showed the highest affinity to α6β1 and α7β1 integrins and furthermore, laminin-121 most effectively supported neurite outgrowth. Together, this suggests that the β2 laminins have higher affinity for integrins than the β1 laminins.
Sasaki
Takako
T
Max-Planck-Institut für Biochemie, Martinsried, Germany. tsasaki@molmed.uni-erlangen.de
Takagi
Junichi
J
Giudici
Camilla
C
Yamada
Yoshihiko
Y
Arikawa-Hirasawa
Eri
E
Deutzmann
Rainer
R
Timpl
Rupert
R
Sonnenberg
Arnoud
A
Bächinger
Hans Peter
HP
Tonge
David
D
D000818:Animals; D002460:Cell Line; D002850:Chromatography, Gel; D002942:Circular Dichroism; D057809:HEK293 Cells; D006801:Humans; D066298:In Vitro Techniques; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000166:cytology; D007797:Laminin / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D011994:Recombinant Proteins / Q000378:metabolism / Q000648:ultrastructure; D012685:Sepharose / Q000031:analogs & derivatives / Q000737:chemistry; D014162:Transfection
D016023:Integrins; D007797:Laminin; D011994:Recombinant Proteins; C037405:heparin-sepharose; C058783:laminin beta2; C084098:laminin A; D012685:Sepharose; C082908:integrin alpha7beta1