Alkaline Phosphatase Expression in Human Chorionic Villi

Abstract

The physicochemical properties and electrophoretic mobility of different isoforms of alkaline phosphatase were studied in chorionic villi. Based on selective inactivation and inhibition studies (thermal stability, inactivation by urea, EDTA and L(+)ascorbic acid and L-amino acid inhibition), evidence was obtained for the existence of two distinct types of alkaline phosphatase in trophoblast cells. One type is peculiar to chorionic villi while the other is also found in term placenta. Both show two isoforms. These two isoforms were observed with polyacrylamide gel electrophoresis, carried out at pH 6.0 and 9.5. It is suggested that the qualitative and quantitative methods of alkaline phosphatase analysis could be used for first trimester fetal diagnosis of severe infantile hypophosphatasia and for understanding genetic control during early fetal development.

STUDYING THE EFFECTS OF SOME COMPOUNDS AND IONS ON Escherichia coli ALKALINE PHOSPHATASE ACTIVITY

“…Fig. ( 4), (10) Illustrates the inhibition of EDTA for E.coli ALP activity.Urea inhibits the activity of the enzyme via blocking the active site.This result confirms with the results arrived at by [45].They found that the activity of ALP extracted from human choronic villi is being inhibited by Urea,EDTA , L-(+)ascorbic acid and Lamino acid. Fig.…”

Alkaline Phosphatase of Cancerous Larynx Tissue in Comparison with the Placental Enzyme: Biochemical and Histochemical Studies

“…Trp partially inhibited the tumor-specific ALP (TSALP). These two aromatic amino acids have previously been found to inhibit laryngeal tumor ALP and other oncofetal ALPS (13,14,17,18) Leu inhibited ALP of tumor cells and blood vessels but not that of the interstitial fibrous tissue. The difference in the percentage inhibition between that caused by Leu and that affected by Phe suggests that the vascular ALP comprises about 50% of the total pool and thus makes the major contribution to the pool.…”

“…Phe sensitivity and heat stability are characteristics of the Regan and Nagao isoenzymes (6,20,21). Trp, which partially inhibited the TSALP, has been found to inhibit other heat-resistant ALPS (12,13). Leu, which inhibits the Nagao but not the Regan isoenzyme (23,24), profoundly inhibited the TSALP.…”

Extracellular vesicles in spontaneous preterm birth

“…19,[29][30][31][32] Exosomes' functional role in pre-eclampsia, gestational diabetes pathogenesis, placental dysfunctions, and their biomarker potentials has been well reported. [33][34][35][36][37][38][39][40] This was made possible partly due to the presence of placental alkaline phosphatase (PLAP), an enzyme present in placental trophoblast cells 41 and expressed on the membrane of trophoblast-derived exosomes. Tagging PLAP has been used as a method of isolating and characterizing exosomes which facilitated studying them as a snapshot of placental function.…”