Cysteine-rich intestinal protein binds zinc during transmucosal zinc transport

Journal Article · Fri Nov 01 00:00:00 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]

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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), Vol. 88:21; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

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