Total 141 AA. MW: 16.2 kDa (calculated). UniProtKB acc.no. Q96NZ9 (Val21– Gln151). N-Terminal His-tag (10 extra AA). Protein identity confirmed by LC-MS/MS.
Amino Acid Sequence
Purity as determined by densitometric image analysis: >85%
14% SDS-PAGE separation of Human PRAP1:
1. M.W. marker – 97, 66, 45, 31, 21, 14 kDa
2. reduced and boiled sample, 2.5μg / lane
3. non-reduced and non-boiled sample, 2.5μg / lane
< 1.0 EU/ug
Filtered (0.4 μm) and lyophilized in 0.5 mg/ml in 0.05 M phosphate buffer, 0.075 M NaCl, pH 7.4
Add 200μl of deionized water to prepare a working stock solution of 0.5 mg/ml and let the lyophilized pellet dissolve completely. Product is not sterile! Please filter the product by an appropriate sterile filter before using it in the cell culture.
Western blotting, ELISA
At ambient temperature. Upon receipt, store the product at the temperature recommended below.
Store the lyophilized protein at –80 °C. Lyophilized protein remains stable until the expiry date when stored at –80 °C. Aliquot reconstituted protein to avoid repeated freezing/thawing cycles and store at –80 °C for long term storage. Reconstituted protein can be stored at 4 °C for a week.
Quality Control Test
BCA to determine quantity of the protein.
SDS PAGE to determine purity of the protein.
LAL to determine quantity of endotoxin.
This product is intended for research use only.
Proline-rich acidic protein 1 (PRAP1) was originally isolated from mouse uterus in 1997. It is abundantly expressed in the uterus during late pregnancy but disappears from the uterus within 3 days after birth. It was therefore termed pregnant-specific uterus protein (PSUP). This protein is proline rich and acidic, thus it is also called proline-rich acidic protein 1 (PRAP1). Human genes of PRAP1 are located on chromosome 10q26.33. Proline-rich acidic protein 1 (PRAP1) is a secretory protein of 149 amino acids, with a 20 amino acids length signal peptide at its N-terminal. Human PRAP1 is abundantly expressed in the epithelial cells of the human liver, kidney, gastrointestinal tract and cervix. PRAP1 expression was found to be significantly down-regulated in hepatocellular carcinoma and right colon adenocarcinoma compared with the respective adjacent normal tissues. The function of PRAP1 is largely unknown. It is presumed that PRAP1 may play an important role in maintaining normal growth homeostasis in epithelia since PRAP1 protein was found to be over-expressed in apoptotic cells.  PRAP1 protein, has a domain similar to EF hand which function as a calcium binding site. Other proline-rich acidic proteins such as salivary proline-rich acidic proteins could bind calcium to maintain the concentration of ionic calcium and prevent bacterial adhesion. Small proline-rich proteins in the stratified squamous epithelium form a unique protective barrier against environmental insults. Proinflammatory cytokines are inducers of small proline-rich protein 1B expression in squamous metaplasia. Therefore, PRAP1 may function in modulating cell proliferation and apoptosis in the uterus and regulating immune protection for the embryo within the uterus. Overexpression of PRAP1 in cancer cells can inhibit cell growth. It has been suggested that PRAP1 may be involved in normal epithelial cell homeostasis as a negative regulator and that the down-regulation of PRAP1 in cancer cells may lead to dysregulated cell growth. The function and regulation of PRAP1 in the uterus remain unknown. Microarray analysis indicates that PRAP1 is down-regulated in the preimplantation day 3.5 uterus, but is greatly upregulated after implantation.