(PTU), a known tyrosinase inhibitor , was tested as a positive control to assess in vivo alterations in pigmentation (Figure 5).
The cells were resuspended in 5 mL of 25 mM sodium phosphate buffer (pH 7.4), 1.0 mM EDTA, 0.1 mM DDT, 0.1 mM Phenylthiourea
(PTU), and 0.1 mM phenylmethylsulfonyl fluoride (PMSF).
This process can be inhibited when phenoloxidase is irreversibly deactivated by phenylthiourea
(PTU), a copper chelating agent (Laskin & Piccinini 1986).
Hind legs were severed with fine scissors and the exuded hemolymph collected in sterile centrifuge tubes, containing a few crystals of phenylthiourea
(Eastman-Kodak, U.S.A) to inhibit phenoloxidase activity.
An alternative explanation may be that the 5"-hydroxyl group of 3 chelates to one or both of the copper ions within the active site cleft, similar to the previously described binding of phenylthiourea
(Klabunde et al., 1998).
Just as the ability to taste the bitter compound phenylthiourea
(PTC) is inherited, anosmia--the inability of a person with otherwise normal olfactory abilities to detect a specific odor--is thought to be genetically based in some cases.
We treated growing cultures of Laomedea flexuosa with substances we suspected would interfere with the hardening of the perisarc (L-cysteine, phenylthiourea
) and those we expected would stimulate it (dopamine, N-acetyldopamine).
), was inadvertently inhaled by two lab workers.
Each replicate of 10 larvae was homogenized in 160 [[micro]liter] 0.15 M phosphate buffered saline (PBS) + 1 mM phenylthiourea
+ 1 mM ethylene-diamine-tetra acetic acid (pH 7.4).
The measurement of taste sensitivity to phenylthiourea
. Ann Eugen.