The innovation engine for new materials

Bernice McLaurin

2009 Summer Intern

University: 

Jackson State University

Major: 

Chemistry

Mentor(s): 

Joanna Deek

Faculty Sponsor(s): 

Cyrus R. Safinya

Faculty Sponsor's Department(s): 

Cellular, Molecular and Developmental Biology

Project Title: 

SALT DEPENDENCE OF NEUROFILAMENT GEL PHASE BEHAVIOR

Project Description: 

Neurofilament proteins (NFs) are believed to be involved in the maintenance of neuronal cell function and structure, and are present within the cytoskeleton of neuronal cells. The accumulation of NFs in the neuronal cell axons of the diseased cells inhibit transportation of particles through the axon; this eventually results in neuronal cell death. NFs self-assemble to form the extended filament with 10nm diameter and are classified into 3 subunits: NF-Low, NFMedium, and NF-High, this is dependent by the relative length of their tail domains and have corresponding molecular weights of 63kDa, 105kDa, and 125kDa. By studying the NF network assembly and interactions the electrostatic attraction or repulsion between NFs is able to be altered using various salt concentrations. Increased monovalent and divalent salt concentrations in the reassembly buffer, in addition to sidearm interactions, have been implicated in more extensive longitudinal growth of the filaments. Crude protein containing NFs must be separated starting from subunits isolated using anion exchange. NF Phase behavior is characterized by optical microscopy, Transmission Electron Microscope, and Small X-ray Scattering. NF-Medium and NF-High behave differently due to variant inherent charge. By using a harged system, salts allow us to probe their interactions and total effective charge.