Naomi H. Moskowitz

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Synaptic plasma membrane preparations from brain tissue have endogenous Ca2+-dependent phospholipase A2 activity. Characterization of this activity revealed that it was maximally active at 10(-7)-10(-5) M Ca2+ and pH 7.0. The enzyme had a Km of 62.0 microM and a Vmax of 98.0 nmol/mg/h. Calmodulin and prostaglandin F2 alpha stimulated phospholipase A2(More)
The role of CD28-mediated signals in T helper cell maturation is not fully understood. We tested the requirement for costimulation through CD28 in several systems of CD4+, T cell differentiation. In vivo priming of mice with genetic disruption of CD28 (CD28-/-) yielded normal levels of antigen-specific interferon gamma production but markedly diminished(More)
Naive CD4+ T helper cells (Th) differentiate into one of two well-defined cell types during immune responses. Mature Th1 and Th2 cells regulate the type of response as a consequence of the unique cytokines that they secrete. CD4 serves a prominent role in potentiating antigen recognition by helper T cells. We have examined the role of CD4 in peripheral T(More)
The outcome of murine infection with Leishmania major is regulated by major histocompatibility complex class II-restricted T helper cells. Invariant chain-deficient (Ii -/-) mice have impaired ability to present major histocompatibility complex class II-restricted antigens, and reduced numbers of CD4+ T cells. Despite these deficits, C57BL/6 Ii -/- mice(More)
The assembly of clathrin into baskets or cages in vitro may depend on formation of complex between clathrin and a polypeptide doublet migrating in the 30000-mol.wt. region. Clathrin with several associated proteins was isolated from coated-vesicle fractions of bovine cerebral cortex. Most associated proteins were separated by Sepharose 4B column(More)
Endogenous phospholipase A2 activity of brain synaptic vesicles was Ca2+ -dependent and was increased by prostaglandin F2 alpha, calmodulin, adenosine 3', 5' -monophosphate, and adenosine triphosphate, whereas the activity was inhibited by prostaglandin E2 in the absence or presence of calmodulin. Light-scattering measurements demonstrated that stimulation(More)
Brain synaptic vesicle phospholipase A2 (PLA2) activity was characterized. It is Ca2+-dependent and has a pH optimum of 9.0. The enzyme has a Km of 60 microM and a Vmax of 2.0 nmol/mg/h. Calmodulin, prostaglandin F2 alpha, and cAMP, and ATP all increased the Vmax of the enzyme. Prostaglandin E2 inhibited the Vmax in the presence or absence of calmodulin.(More)
The association of calmodulin with brain synaptic vesicle proteins was analyzed. Scatchard analysis of [125I]calmodulin binding to brain synaptic vesicles revealed one high-affinity, low-binding-capacity, Kd = 1.0 (+/- 0.15) nM, Bmax = 4.1 (+/- 0.6) pmol/mg, and one low-affinity high-binding-capacity site, Kd = 177. (+/- 12.0) nM and Bmax = 202 (+/- 15.0)(More)
A systematic characterization of the affinity of calmodulin for brain coated vesicles was undertaken. Binding of 125I-labeled calmodulin to coated vesicles was saturable and competed with unlabeled calmodulin, but not with troponin-C. Scatchard analysis revealed one high-affinity, low-capacity binding site, KD = 3.9 +/- 0.6 nM, Bmax = 16.3 +/- 2.4 pmol/mg,(More)