Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Light-chain binding sites on renal brush-border membranes

Journal Article · · American Journal of Physiology; (USA)
OSTI ID:6728004
; ;

Immunoglobulin light chains are low-molecular-weight proteins filtered at the renal glomerulus and catabolized within the proximal tubular epithelium. Excessive production and urinary excretion of light chains are associated with renal dysfunction. They also interfere with proximal renal tubule epithelial functions in vitro. We studied the binding of 125I-labeled kappa- and lambda-light chains, obtained from the urine of multiple myeloma patients, to rat and human renal proximal tubular brush-border membranes. Light-chain binding to brush borders was also demonstrated immunologically by flow cytometry. Computer analysis of binding data was consistent with presence of a single class of low-affinity, high-capacity, non-cooperative binding sites with relative selectivity for light chains on both rat and human kidney brush-border membranes. The dissociation constants of light chains ranged from 1.6 X 10(-5) to 1.2 X 10(-4) M, and maximum binding capacity ranged from 4.7 +/- 1.3 X 10(-8) to 8.0 +/- 0.9 X 10(-8) (SD) mol/mg protein at 25 degrees C. Kappa- and lambda-light chains competed with each other for binding with comparable affinity constants. Competition by albumin and beta-lactoglobulin, however, was much weaker, suggesting relative site selectivity for light chains. These binding sites probably function as endocytotic receptors for light chains and possibly other low-molecular-weight proteins.

OSTI ID:
6728004
Journal Information:
American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 258; ISSN 0002-9513; ISSN AJPHA
Country of Publication:
United States
Language:
English

Similar Records

Binding of cadmium metallothionein to isolated renal brush border membranes (41122). [Rabbits]
Journal Article · Fri May 01 00:00:00 EDT 1981 · Proc. Soc. Exp. Biol. Med.; (United States) · OSTI ID:6339997
Binding and degradation of /sup 125/I-insulin by isolated rat renal brush border membranes: evidence for low affinity, high capacity insulin recognition sites
Journal Article · Sat Oct 01 00:00:00 EDT 1988 · J. Membr. Biol.; (United States) · OSTI ID:6270838
Specific binding of lactoferrin to brush-border membrane: Ontogeny and effect of glycan chain
Journal Article · Thu Mar 31 23:00:00 EST 1988 · American Journal of Physiology; (USA) · OSTI ID:6749084

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
CELL FLOW SYSTEMS
CELL MEMBRANES
CPB
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
EPITHELIUM
GLOBULINS
IMMUNOGLOBULINS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
MAMMALS
MAN
MEMBRANE PROTEINS
MEMBRANES
MOLECULAR WEIGHT
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PRIMATES
PROTEINS
RADIOISOTOPES
RATS
RECEPTORS
RODENTS
TISSUES
TRACER TECHNIQUES
VERTEBRATES