Phenylalanine transport in utero.

Phenylalanine transport in utero.

Specificity of the tyrosine-phenylalanine transport system in Bacillus subtilis.

l-Tyrosine and l-phenylalanine enter cells of Bacillus subtilis via a system of active transport that exhibits complex kinetic behavior. The specificity of the transport system was characterized both at low concentrations of transport substrate (where affinity for l-tyrosine or l-phenylalanine is high but capacity is low) and at high concentrations (where affinity is low but capacity is high). ...

Relationships between mucosal hydrolysis and transport of two phenylalanine dipeptides.

In order to investigate the source of free amino acids found in the gut lumen during absorption of dipeptides, as well as evaluating the role of brush border peptidases in the mucosal hydrolysis of dipeptides during absorption, rates of dipeptide disappearance and appearance of hydrolytic products were measured during perfusion of rat jejunum and ileum in vivo with buffered and unbuffered 10 mM...

In-Utero Limb Amputation

A preterm (32wks, 1.4 kg) female baby, born to a multigravida mother by emergency section in a tertiary care center (no history of consanguinity, exposure to teratogens, radiation, trauma, smoking or alcohol intake during pregnancy), presented with amputated right leg attached with a skin tag to the remaining part of right lower limb. No other defects were present. Ultrasound abdomen and craniu...

Mechanism of phenylalanine regulation of phenylalanine hydroxylase.

The mechanism of phenylalanine regulation of rat liver phenylalanine hydroxylase was studied. We show that phenylalanine "activates" phenylalanine hydroxylase, converting it from an inactive to active form, by binding at a true allosteric regulatory site. One phenylalanine molecule binds per enzyme subunit; it remains at this site during catalytic turnover and, while there, cannot be hydroxylat...