A new type of intramolecular H ⋯ H ⋯ H interaction involving N–H ⋯ H(Ir)⋯ H–N atoms. Crystal and molecular structure of [IrH(η¹-SC₅H₄NH)₂(η²-SC₅H₄N)(PCy₃)]BF₄·0.72CH₂Cl₂

Abstract

The iridium complexes, [Irk (ql-SC5H4N k)2(q2-SC5H4N) ( PCy,)] (B F4), 1, and [I rH(q1-SC5H4N H )*(q -SC5H4N H )2(PCy3)1-(BF4)2, 2, [Cy = cyclohexyl] in the solid state and in CD2C12 solution contain a new type of intramolecular H...H...H i nt e ra ct i o n co nta i n ed i n tenm e m be red bi c ycl i c ri n g s S-C-N-H H ( I r)". H-N-C-S def i n ed by the two 2 -py r i d i n i u m t h i o I ate ligandscoordinated in a monodentatefashion viasulfurto an iridium atom.

Extracellular Cleavage of the Vascular Endothelial Growth Factor 189-Amino Acid Form by Urokinase Is Required for Its Mitogenic Effect

“…Both isoforms could bind to each VEGF receptor constitutively expressed in heparan sulfate-deficient CHO cells, although Pl-V189 exhibited a 3-4-fold reduced affinity for both VEGF receptors. These results contrast with the observation that iodinated 50-kDa form and Pl-V189 bound only to a low number of binding sites on ACE cells, presumably Flt-1 receptors, which are expressed in ACE cells (30). Accordingly, Pl-V189 elicited a 50-fold reduced mitogenic effect on ACE cells as compared with uPA-V189.…”

Biosynthesis of Vascular Endothelial Growth Factor-D Involves Proteolytic Processing Which Generates Non-covalent Homodimers

“…All three are broadly expressed on endothelial cells throughout embryonic development (8,9), but, as embryogenesis proceeds, VEGFR-3 becomes restricted to venous endothelial cells and then to endothelial cells of the lymphatic vessels (10). VEGF binds to VEGFR-1 and VEGFR-2 (9,11,12), whereas VEGF-B and PlGF bind only to VEGFR-1 (13,14). In contrast, VEGF-C and VEGF-D bind VEGFR-2 and VEGFR-3 (3,15).…”

Receptor Chimeras Indicate That the Vascular Endothelial Growth Factor Receptor-1 (VEGFR-1) Modulates Mitogenic Activity of VEGFR-2 in Endothelial Cells

“…All of these isoforms have been shown to bind to both VEGFR-1 and VEGFR-2 (3,4). On the other hand, placenta growth factors (PIGFs) have been shown to bind VEGFR-1 only (4,5). VEGF is a potent stimulator of angiogenesis in vivo and growth, migration, and differentiation of endothelial cells in vitro (6 -8).…”