Protein-protein interactions in TRAF3.

TNF-receptor-associated factors (TRAFs) are intracellular proteins that bind to the cytoplasmic portion of TNF receptors and mediate downstream signaling. The six known TRAF proteins play overlapping yet distinct roles in controlling immune responses as well as cellular processes such as activation of NF-kappaB and JNK signaling pathways. For example, CD40 binds to TRAF2, TRAF3 and TRAF6 to control B cell differentiation, proliferation and growth.

LMP1 protein from the Epstein-Barr virus is a structural CD40 decoy in B lymphocytes for binding to TRAF3.

Epstein-Barr virus is a human herpesvirus that causes infectious mononucleosis and lymphoproliferative malignancies. LMP1 (latent membrane protein-1), which is encoded by this virus and which is essential for transformation of B lymphocytes, acts as a constitutively active mimic of the tumor necrosis factor receptor (TNFR) CD40. LMP1 is an integral membrane protein containing six transmembrane segments and a cytoplasmic domain at the C terminus that binds to intracellular TNFR-associated factors (TRAFs).

Characterization of the PR domain of RIZ1 histone methyltransferase.

RIZ1 (PRDM2) and PRDI-BF1 (PRDM1) are involved in B cell differentiation and the development of B cell lymphomas. These proteins are expressed in two forms that differ by the presence or absence of a PR domain. The protein product that retains the PR domain is anti-tumorigenic while the product that lacks the PR domain is oncogenic and over-expressed in tumor cells.

Fluorescence Analysis of the Fibrinolytic Principle (FP) from Agkistrodon acutus Venom.

The conformation and the properties of the fibrinolytic principle (FP) from Agkistrodon acutus venom were studied by chemical modification and fluorescence spectroscopy. Results showed that there are more than one tryptophan (Trp) residue in the FP molecule and they are located in the more hydrophobic core, could be quenched by acrylamide (Acr), a polarized quencher without electric charge. The collisional quenching constants of FP at different concentrations of Acr were calculated in terms of Stern-Volmer equation, and the fraction of the Trp quenched was obtained by the modified Stern-Volmer equation as 83%.

Biochemical Properties of Bound-Ca(2+) in Fibrinolytic Principle (FP) Separated from Agkistrodon acutus Venom.

It has been determined that each FP molecular contains one Ca(2+)-binding site. By the use of fluorescence probe Tb(3+), the distance between Tb(3+) and tryptophan (Trp) residue was obtained to be 0.375.

Purification of NAD glycohydrolase from Agkistrodon acutus venom.

NAD glycohydrolase (NADase) from Agkistrodon acutus venom was purified to electrophoretic homogeneity by a fast, reproducible 3-step procedure including Q Sepharose Fast Flow, Superdex 75, and Mono S column chromatography. This new procedure gave a 15.6-fold purification with a recovery yield of 7.