alpha2-macroglobulin modulates the immunoregulatory function of the lipocalin placental protein 14.
Publication/Presentation Date
10-15-2000
Abstract
Human placental protein 14 (PP14; also known as glycodelin and progesterone-associated endometrial protein) is an immunosuppressive protein of the lipocalin structural superfamily. Mechanisms regulating serum PP14's immunosuppressive activity remain to be elucidated. In the present study, an interaction between PP14 and a major serum protein carrier, alpha(2)-macroglobulin (alpha(2)M), was documented for the first time. Using native gel electrophoresis, we showed that PP14, as well as its alternative splice variant PP14.2, binds to both alpha(2)M and methylamine-activated (MA)-alpha(2)M. Cross-competition studies demonstrated that the variants compete for binding to alpha(2)M. PP14 bound to alpha(2)M and MA-alpha(2)M with K(d) values of 167+/-70 and 221+/-56 nM (means+/-S.D.) respectively, as determined by surface plasmon resonance. Significantly, the addition of alpha(2)M or MA-alpha(2)M to a T-cell proliferation assay strongly potentiated the inhibitory capacity of PP14. On the basis of these findings, alpha(2)M emerges as the first serum protein that can physically associate with, and thereby regulate, PP14. Moreover, this represents the first documented interaction between the protein carrier alpha(2)M and a lipocalin protein.
Volume
351 Pt 2
Issue
Pt 2
First Page
503
Last Page
508
ISSN
0264-6021
Published In/Presented At
Riely, G. J., Rachmilewitz, J., Koo, P. H., & Tykocinski, M. L. (2000). alpha2-macroglobulin modulates the immunoregulatory function of the lipocalin placental protein 14. The Biochemical journal, 351 Pt 2(Pt 2), 503–508.
Disciplines
Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods
PubMedID
11023837
Department(s)
Administration and Leadership
Document Type
Article