Justin A. Lemkul

Learn More
Proper treatment of nonbonded interactions is essential for the accuracy of molecular dynamics (MD) simulations, especially in studies of lipid bilayers. The use of the CHARMM36 force field (C36 FF) in different MD simulation programs can result in disagreements with published simulations performed with CHARMM due to differences in the protocols used to(More)
GridMAT-MD is a new program developed to aid in the analysis of lipid bilayers from molecular dynamics simulations. It reads a GROMACS coordinate file and generates two types of data: a two-dimensional contour plot depicting membrane thickness, and a polygon-based tessellation of the individual lipid headgroups. GridMAT-MD can also account for proteins or(More)
Amyloid fibrils represent a stable form of many misfolded proteins associated with numerous diseases. Among these are Parkinson's disease (alpha-synuclein), Type II diabetes (islet amyloid polypeptide), and Alzheimer's disease (amyloid beta-peptide, Abeta). The appearance of Abeta fibrils in neural tissue is a hallmark of Alzheimer's disease, and many(More)
The etiology of Alzheimer's disease is considered to be linked to interactions between amyloid beta-peptide (Abeta) and neural cell membranes. Membrane disruption and increased ion conductance have been observed in vitro in the presence of Abeta, and it is assumed that these same phenomena occur in the brain of an individual afflicted with Alzheimer's. The(More)
The pathogenic aggregation of the amyloid β-peptide (Aβ) is considered a hallmark of the progression of Alzheimer's disease, the leading cause of senile dementia in the elderly and one of the principal causes of death in the United States. In the absence of effective therapeutics, the incidence and economic burden associated with the disease are expected to(More)
The behavior of the amyloid β-peptide (Aβ) within a membrane environment is integral to its toxicity and the progression of Alzheimer's disease. Ganglioside GM1 has been shown to enhance the aggregation of Aβ, but the underlying mechanism is unknown. Using atomistic molecular dynamics simulations, we explored the interactions between the 40-residue alloform(More)
Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight(More)
Because the amyloid beta-peptide (Abeta) functions as approximately half of the transmembrane domain of the amyloid precursor protein and interaction of Abeta with membranes is proposed to result in neurotoxicity, the association of Abeta with membranes likely is important in the etiology of Alzheimer's disease. Atomic details of the interaction of Abeta(More)
Numerous studies have concluded that the interaction of the amyloid β-peptide (Aβ) and cellular membranes contributes to the toxicity and cell death observed in the progression of Alzheimer's disease. Aggregated Aβ species disrupt membranes, leading to physical instability and ion leakage. Further, the presence of Aβ on the membrane surface increases the(More)
Alzheimer's disease is a progressive, neurodegenerative disorder that is the leading cause of senile dementia, afflicting millions of individuals worldwide. Since the identification of the amyloid beta-peptide (Abeta) as the principal toxic entity in the progression of Alzheimer's disease, numerous attempts have been made to reduce endogenous Abeta(More)