Different expressions of cardiac biomarkers between different types of acquired right ventricular outflow tract abnormality in monochorionic twins.

Objective: To investigate the differences in amniotic fluid cardiac biomarkers and clinical features among types of right ventricular outflow tract (RVOT) abnormality in monochorionic (MC) twins.

Method: This prospective study included MC twins that underwent laser surgery. Recipient or larger twins (group A) and donor or smaller twins (group B) were assessed and divided into those with a normal right ventricular outflow tract (normal RVOT), functional pulmonary atresia (fPA), or pulmonary stenosis (PS).

Conformational changes in the catalytic region are responsible for heat-induced activation of hyperthermophilic homoserine dehydrogenase.

When overexpressed as an immature enzyme in the mesophilic bacterium Escherichia coli, recombinant homoserine dehydrogenase from the hyperthermophilic archaeon Sulfurisphaera tokodaii (StHSD) was markedly activated by heat treatment. Both the apo- and holo-forms of the immature enzyme were successively crystallized, and the two structures were determined. Comparison among the structures of the immature enzyme and previously reported structures of mature enzymes revealed that a conformational change in a flexible part (residues 160-190) of the enzyme, which encloses substrates within the substrate-binding pocket, is smaller in the immature enzyme.

Inhibition of homoserine dehydrogenase by formation of a cysteine-NAD covalent complex.

Homoserine dehydrogenase (EC 1.1.1.