Technical Data
NaPi-4, NT (Npt2a)
Inorganic phosphate (Pi) levels are hormonally regulated that affects the physiological activity of bone, kidney, and small intestine. Majority of the Pi is absorbed in the small intestine and reabsorbed in the proximal tubules in the kidney. At least 4 groups of structurally and funcationally related proteins are in involved in Pi transport: Type I-related NaPi transporters designated NPT1, Npt1, and NaPi-1 respectively in humans, mouse, and rabbit are expressed in the kidney and liver. Its expression and activity are not regulated by Pi deprivation or parathyroid hormone (PTH) and its role in Pi-homeostasis is not clear. Type IIa-related cotransporters, designated NaPi-2 in rat, NaPi-3 or NPT2 in humans, NaPi-4 in opposum, NaPi-5 in flounder vessel, NaPi-6 or Npt-2 in mouse, and NaPi-7 in rabbit, is the primary target for Pi regulation by dietary, hormonal, and tubular Pi reabsorption. Deletion of Npt2 gene produces severe Pi wasting. Type II transporters are expressed in kidney, brain, lung, bone and small intestine. Type IIb, designated as NaPi-IIB or NaPi-2b in rat/mouse, and NaPi-3b in human, is closely related isoform of the NaPi-2 family. It is expressed in small intestine and lung. Type III NaPi transporters, originally described as a family of cell surface receptors for gibbon ape leukemia virus (GALV) and murine amphotropic retrovirus (A-MuLv), share very low (<20%) sequence homology with Type I and II proteins, and are found in most tissues. Human homolog are now desganted as PiT1 (also known as GALV receptors or GLVR1) and PiT2 (A-MuLV receptors or GLVR2 or Ram1). Pit1 and Pit2 are ~62% related and predicted to contain 10 TM domains that is in contrast with Type 1/2 transporters (6-8 TM). The N and C-termini are predicted to be cytoplasmic.

Suitable for use in ELISA, Western Blotting. Other applications not tested.

Recommended Dilution:
Western Blot: 1:1000-1:5000 for antiserum and 1-10ug/ml for affinity pure antibody using Chemiluminescence technique. NPT2a apparent mol wt is 80-90kD, and under reducing conditions 2 bands of 40-50kD are observed. It may also form multimeric structures (170 and 200kD). (see Murer et al 2000)
ELISA: 1:10,000-50,000 for neat serum and 0.5-1ug/ml for affinity pure. Control peptide can be used to coat ELISA plates at 1ug/ml.

Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot and add glycerol (40-50%). Freeze at -20C. Aliquots are stable for at least 12 months at -20C. 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.
PabIgGAffinity Purified
100ul-20CBlue IceOpossumRabbit
As reported
A 20 AA synthetic peptide within the cytoplasmic, N-terminus region of Opossum NaPi-4/NPT2a was synthesized, conjugated to KLH
Affinity purified over the control-peptide Sepharose
Supplied as a liquid in PBS, pH 7.4 and 0.1% sodium azide, 40% glycerol.
Peptide is specific for opossum Napi-4/npt2a. This sequence is not conserved in mouse, rat, human and other species Npt2a. No significant sequence homology is observed with other Pi-transporters (Type-I, III, or IV) transporters. Antibody crossreactivity in various species is not established.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1). Magnin S et al (1993) PNAS 90, 5979; Collins JF et al (1996) FASEB J 8, 862; Hartman CM et al (1996) PNAS 93, 7409. (2) Murer H et al (2000) Physiolo. Rev. 80, 1373 (review); Werner A et al (2001) Am. J. Physiol. Integ. Comp. Physiol. 280, R301 (review).