The work on the internal dynamics of protein G was concluded. Collaboration with the Clore group is continuing with the solution structure of a complex between zinc-finger portion of the regulatory domain of protein kinase C (PK-C) and small phorbol ester type ligand. The work on the solution conformation of a cyclic hexapeptide ligand for the SH2 domain of PI3 kinase was finished. Four O-linked glycopeptides of an active sequence, Ser-Ile-Lys-Val-Ala- Val, from the long arm of the A-chain of laminin, were prepared, purified and characterized. Two of these were shown to bind PC12 brain tumor cells and these same two compounds also inhibited laminin binding to PC12 cells. The lactose containing glycopeptide is being reinvestigated in the binding assay. A study on the synthesis and inhibition of MOLT-4 derived deoxycytidylate deaminase (dCMPD) by derivatives of the known anti-cancer agent 2-oxo- pyrimidine riboside, zebularine, was completed. A follow-up study on the complete metabolism of zebularine in MOLT-4 and its role in deoxypyrimidineribonucleotide biosynthesis is in progress.
