At the
isoelectric point, protein-water interactions are minimal, whereas aggregates of weak proteinprotein hydrophobic interactions are present, causing precipitation of proteins (FENNEMA, 1996).
Fumed alumina has an
isoelectric point around pH 10 and should, therefore, be cationically charged in typical coating formulations (pH 3-9).
The calculated molecular mass of the mature protein is 38.2 kDa and
isoelectric point is 6.13.
The
isoelectric points (pI) and molecular weights (kDa) of these spots are shown in Table 1.
The pka value (8.2) and the
isoelectric points (13.24) [21] of RANH.
tuberculatum, number of the spots, protein score, total ion score, peptide sequence, number of entry in the database (NCBI), the identity of the protein, species, relative molecular mass (Mr, kDa) and
isoelectric point (pI), (literature), relative molecular mass (Mr, kDa) and
isoelectric point (pI) (experimental), coverage (%), access (UniProt) and Biological Process.
When pH is higher than the
isoelectric point (IEP) of the suspension, under this condition, the high ionic strength in the solution will cause the adsorbate to dangle into the solution.
This, in turn, causes a variation in its pH, which is reflected in its remoteness from its
isoelectric point; therefore, its low solubility in the solvent.
The EA of all PI decreased from pH 2-4.with the lowest EA obtained around the
isoelectric point (pH 4).
In this test, the
isoelectric point of oil bodies was at [zeta]-potential of zero (these figures not show).
Isoelectric point and charge heterogeneity were determined using iCE3 Capillary IEF System (ProteinSimple, USA).
However, in certain cases, a compromise should be found between the pH ensuring stability of the drug substance, such as for peptides requiring alkaline pH or proteins at pH close to the
isoelectric point, and the physiological one.