Cysteine-rich intestinal protein binds zinc during transmucosal zinc transport

Journal Article · Fri Nov 01 04:00:00 EST 1991 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.88.21.9671· OSTI ID:5701990

Hempe, J M; Cousins, R J ^[1]

---

1. Univ. of Florida, Gainesville (United States)

The mechanism of zinc absorption has not been delineated, but kinetic studies show that both passive and carrier-mediated processes are involved. The authors have identified a low molecular mass zinc-binding protein in the soluble fraction of rat intestinal mucosa that could function as an intracellular zinc carrier. The protein was not detected in liver or pancreas, suggesting a role specific to the intestine. The protein binds zinc during transmucosal zinc transport and shows signs of saturation at higher luminal zinc concentrations, characteristics consistent with a role in carrier-mediated zinc absorption. Microsequence analysis of the protein purified by gel-filtration HPCL and SDS/PAGE showed complete identity within the first 41 N-terminal amino acids with the deduced protein sequence of cysteine-rich intestinal protein. These investigators showed that the gene for this protein is developmentally regulated in neonates during the suckling period, conserved in many vertebrate species, and predominantly expressed in the small intestine. Cysteine-rich intestinal protein contains a recently identified conserved sequence of histidine and cysteine residues, the LIM motif, which our results suggest confers metal-binding properties that are important for zinc transport and/or functions of this micronutrient.

• OSTI ID: 5701990
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (United States) Vol. 88:21; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION
AMINO ACID SEQUENCE
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR SYSTEM
CYSTEINE
DAYS LIVING RADIOISOTOPES
DIET
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENDOCRINE GLANDS
EVEN-ODD NUCLEI
GASTROINTESTINAL TRACT
GLANDS
INTERMEDIATE MASS NUCLEI
INTESTINAL ABSORPTION
INTESTINES
ISOTOPES
LIVER
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
METALLOPROTEINS
METALLOTHIONEIN
MOLECULAR STRUCTURE
MUCOUS MEMBRANES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PANCREAS
PORTAL SYSTEM
PROTEINS
RADIOISOTOPES
RATS
RODENTS
THIOLS
UPTAKE
VEINS
VERTEBRATES
ZINC 65
ZINC ISOTOPES