Ligands (Biochemistry)

Chitin Microparticles (CMPs, 1-10um), a special form of the ubiquitous and nontoxic
polysaccharide Chitin (GlcNAc), is capable of inducing a switch in macrophages
from the wound-healing M2 phenotype to the classically activated pro-inflammatory M1
phenotype; which has therapeutic implications in allergy and cancer. We hypothesized
that TLR2 forms a complex with CMPs and Chitin-Binding Proteins (CBPs) at the
surface of peritoneal macrophages and remains with that complex after internalization to
initiate downstream signaling events, leading to the production of the M1 cytokine, TNFalpha.
Our results from experiments performed in RAW 264.7 cells show that TLR2 and
TLR1, but not TLR6, are associated with the CMP binding fraction, and that both TLR1
and TLR2 might be important for M1 activation as a result of CMP phagocytosis. This
project sheds light on CMP as a potential therapeutic agent and provides more evidence
for a phagocytosis-dependent TLR2 signaling pathway.

The planar, dinuclear, tridentate ligands, 1,3,5,7-tetrakis(2-pyridylimino)benzodipyrrole (TAII) and 1,3,5,7-tetrakis(4,6-dimethyl-2-pyridylimino)benzodipyrrole (DiMeTAII) were synthesized and characterized as were all intermediates characterized by both infrared and 1H-NMR spectra. Evidence is presented for the formation of Mo4(OAc)6-(DiMeTAII) (I), the dinuclear analog of Mo2(OAc)3-BAII using UV/Vis to show the delta--->delta* transition typical of the quadruple bond and for the determination of percent molybdenum which is consistent with the proposed structure. A review of recent studies into the field of quadruply bonded metal containing polymers will be discussed along with application of compound (I) in this field.