Penn Medicine

Samuel K. Chacko, Ph.D.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine

Contact Information

Department of Pathobiology
University of Pennsylvania School of Veterinary Medicine
389E/365E VET
3800 Spruce Street
Philadelphia, PA 19104-6051
Phone: (215) 898-5755
Fax: (215) 898-0719
Position: Professor


The major emphasis of the laboratory is the molecular mechanism for the regulation of actin-myosin interaction and contraction in smooth muscle. The roles of myosin-mediated and thin filament-mediated regulation of contraction are investigated. The major area of muscle protein research includes smooth muscle myosin isoforms and the thin-filament-associated proteins, caldesmon and calponin. The cell/molecular basis of contractile dysfunction in the smooth muscle cells is also studied. The two diseases that affect the lower urogenital system in men, urinary outlet obstruction and erectile dysfunction (impotence) are studied in detail to understand the molecular mechanisms for altered actin-myosin interaction and regulation of contraction. The technical approaches include expression of contractile proteins using a baculovirus expression system, site directed mutagenesis, gene knockouts, in situ hybridization, immunohistochemistry, in vitro motility assay & enzymatic assays to study the actin-myosin interaction, and studies using fluorescent labelled proteins to study protein conformation during protein-protein interaction.


Pennsylvania Muscle Institute
Perelman School of Medicine University of Pennsylvania
Director: E. Michael Ostap, Ph.D.

700A Clinical Research Building Philadelphia, PA 19104-6085 Phone: (215) 573-9758 Fax: (215) 898-2653