Embryonic vascular system undergoes a series of complex, highly regulated series of events involving differentiation, migration and association of primitive endothelial cells. This process is termed vasculogenesis. A further remodeling of the primitive vascular system forms the mature cardiovascular system. This process is known as angiogenesis (sprouting of new capillary vessels from pre-existing vasculature). The development of primordia of the heart and large vessels, primary capillary networks in the embryo and the extraembryonic structures in the yolk sac. Angiogenesis accounts for the formation of vasculature into previously avascular organs such as brain and kidney. Angiogenic activity in the adult is required during the normal tissue repair, and for the remodeling of the female reproductive organs (ovulation and placental development). Certain pathological conditions, such as tumor growth and diabetic retinopathy, also require angiogenesis. Study of tumor angiogenesis has led to the identification of several proteins including basic fibroblast growth factor (bFGF) and vascular endothelial growth factor. VEGF acts by interacting with a family of largely endothelial-specific receptor tyrosine kinases that includes VEGFR-1 (flt-1), VEGFR-2 (flk-1/KDR), and VEGFR-3/Flt-4. Disruption of VEGFRs interferes with differentiation of endothelial cells and it is lethal for the embryo.

Angiopoietin 1 is prominently expressed in the myocardium of atrium and ventricle, mesenchymal and smooth muscle cells surrounding most blood vessels, and lung. In the adult, Angiopoietin 1 was also expressed in the heart and liver. Angiopoietin 2 expression is abundant in the dorsal aorta and major aortic branches. Angiopoietin 2 transcripts in fetal liver were restricted to cells at the lumen of hepatic vessels. Angiopoietin 2 was found in tissues that may undergo vascular remodeling (ovary, placenta, and uterus). Defects in Tie-2 have been linked to dominantly negative venous malformation, an error of vascular morphogenesis characterized by dilated serpiginous channels.

A homology-based cloning approach has led to the identification of Angiopoietin 3 (Angpt3, 509aa, chromosome 2) in mouse, and Angiopoietin 4 (ANGPT4, 504aa, chromosome 20p13) in human. Although Angiopoietin 3 and Angiopoietin 4 are more structurally diverged from each other than are the mouse and human versions of Angiopoietin 1 and Angiopoietin 2, they appear to represent the mouse and human counterparts of the same gene locus, as revealed in chromosomal localization studies of all the angiopoietins in mouse and human. Angiopoietin 3 was expressed as multiple mouse tissues. Angiopoietin 4 was expressed primarily in human lung. It is also suggested that Angiopoietin 3 acts as an antagonist. Angiopoietin 4 functions as an agonist.

Angiopoietin 1 (mouse and human: 498aa; ~98% identity) is an angiogenic secreted protein that interact with endothelial specific Tie-2 receptor. It is primarily expressed in developing endothelial cells. During embryonic development, Angiopoietin 1 binds and induces tyrosine phosphorylation of Tie-2. Angiopoietin 1 appears to play a crucial role in mediating matrix and mesenchyme. It mediates blood vessel maturation and stability. Angiopoietin 1 may play a critical role in heart development. Angiopoietin 1 deficient mice mimic the phenotype exhibited by animals deficient in Tie-2. A homolog of Angiopoietin 1, termed Angiopoietin 2 (mouse and human: 496aa; ~85% identity) has recently been identified. It may act an antagonist for Angiopoietin 1 and Tie-2. Angiopoietin 1 and Angiopoietin 2 have ~60% sequence homology.

Suitable for use in ELISA and Antibody Blocking. Not suitable for use in Western Blot due to low molecular weight. Other applications not tested.

ELISA: 50-100ng of control peptide/well Antibody Blocking: 5-10ug per 1ul A2293 (antiserum) or per 1ug A2293-04 (affinity purified antibody). Optimal dilutions to be determined by the researcher.

Lyophilized powder may be stored at 4°C for short-term only. Reconstitute to nominal volume by adding sterile PBS, lightly vortex and mix for 15 min. at RT. The solution can be used or stored in small aliquots at -20ºC or below. Avoid multiple freeze/thaw cycles.

Mouse synthetic peptide

Purified

~1mg/ml

Supplied as a lyophilized powder in PBS, pH 7.5.

This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.