Calcium (Ca+2 or Ca) is the most abundant cation and it is required for many physiological activities such as bone formation and it acts as a second messenger in signal transduction.
However only 1% of Ca is present in ionic form in biological fluids.
Ca concentration is regulated by calcitropic hormones that act on bone, kidney, and intestine.
Extracellular Ca+-levels are sensed and regulated by Calcium Sensing receptor (CASR).
When Ca levels are limiting then it must be taken up by active, transcellular pathways comprising (1) Ca++ entry across apical membrane, (2) cytosolic transport of Ca++ across the cell form apical to basolateral membrane facilitated by a family of low mol wt Calcium binding proteins (CABPs) that include vitamin D3-dependent Ca++ binding proteins (calbindin-D9k, Calbindin-28k, Calretinin, Parvalbumin, S100, calmodulin) and finally (3) an active extrusion of Ca++ through basolateral membrane mediated by Ca++-ATPase and Na+-Ca++ exchangers (NCX).
Ca++ absorption in intestine and its reabsorption in kidney are carried out by Ca++ Transport (CaT) proteins, CaT-1, CaT-2 or Epithelial Ca Channel (ECAC1/ECAC2/CaT-Like (CaT-L) proteins.
CaT2 (rat 723 aa; human 729 aa, chromosome 7q35) is also known as ECAC1 or TRPV5) is ~75% homologous with CAT1.
In contrast to CaT-1, CaT-2 is exclusively expressed in kidney and absent in intestine, brain, heart, liver, lung, skeletal muscle, spleen, thymus, testis, adrenal gland.
It colocalizes with calbindin D28K and Na+ channel exchanger 1 (NCX1).
CaT-2 mediates saturable apical Ca++ uptake by the cells of distal convoluted tubule and connecting segment of nephron where active re-absorption of Ca++ takes place via transcellular route.
CaT-2 has moderate abilities to transport Sr++ and Ba++.
A strong inhibition of CaT-2 mediated Ca++ transport by Cd++ leads to hypercalciurea and renal stone formation.
Applications:Suitable for use in ELISA, Western Blotting.
Other applications not tested.
Recommended Dilution:Western Blot: 1:1000-1:5000 for neat serum and 1-10ug/ml for affinity pure using ECL.
The expected size of Cat-2 is ~85kD.
However, posttranslational modification may alter its size depending upon the species and cell type
ELISA: 1:10,000-1:100,000 using 50-100ng of control peptide/well.
Optimal dilutions to be determined by the researcher.
Storage and Stability:May be stored at 4°C for short-term only.
For long-term storage and to avoid repeated freezing and thawing, aliquot and add glycerol (40-50%).
Freeze at -20°C.
Aliquots are stable for at least 12 months at -20°C.
For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
Further dilutions can be made in assay buffer.
仕様
Size：100ug
Host：rabbit
Source Antibody：rat
Grade：Affinity Purified
Purity：Purified by immunoaffinity chromatography.
Form：Supplied as a liquid in PBS, pH 7.4 and 0.09% sodium azide, 40% glycerol.
Specificity：The peptide is 90% conserved in rabbit and 84% in human Cat-2/ECAC1-1. No significant sequence homology is seen with CaT-1 or other proteins. Antibody reactivity in various species is not known. Control peptide, because of its low MW (<3kD), is not suitable for Western. It should be used for ELISA or antibody blocking experiments (use 5-10 ug control peptide per 1 ug of aff pure IgG or 1 ul antiserum) to confirm antibody specificity (see below).
Isotype：IgG
Calc Applications Abbrev：E WB
Calc Crossreactivity：Rt
Immunogen：A 20-aa peptide sequence near the cytoplasmic C-terminus of rat CaT-2/ECAC1 (1) was synthesized, coupled to KLH
