Kinetic Stability of Long-Lived Human Lens γ-Crystallins and Their Isolated Double Greek Key Domains.

The γ-crystallins of the eye lens nucleus are among the longest-lived proteins in the human body. Synthesized in utero, they must remain folded and soluble throughout adulthood to maintain lens transparency and avoid cataracts. γD- and γS-crystallin are two major monomeric crystallins of the human lens.

Connecting biology and organic chemistry introductory laboratory courses through a collaborative research project.

Modern research often requires collaboration of experts in fields, such as math, chemistry, biology, physics, and computer science to develop unique solutions to common problems. Traditional introductory undergraduate laboratory curricula in the sciences often do not emphasize connections possible between the various disciplines. We designed an interdisciplinary, medically relevant, project intended to help students see connections between chemistry and biology.

Implementation of a project-based molecular biology laboratory emphasizing protein structure-function relationships in a large introductory biology laboratory course.

In introductory laboratory courses, many universities are turning from traditional laboratories with predictable outcomes to inquiry-inspired, project-based laboratory curricula. In these labs, students are allowed to design at least some portion of their own experiment and interpret new, undiscovered data. We have redesigned the introductory biology laboratory course at Brandeis University into a semester-long project-based laboratory that emphasizes concepts and contains an element of scientific inquiry.

Educating young educators: a pedagogical internship for undergraduate teaching assistants.

Although undergraduates have long held a role as teaching assistants for introductory science courses at liberal arts colleges and universities, educational institutions often do not provide these students with opportunities to explore science teaching and pedagogy. At Brandeis University, we designed an internship course to help increase the motivation, understanding, and knowledge of teaching pedagogy for undergraduate teaching assistants that is offered concurrently with their teaching responsibilities. Weekly sessions with faculty mentors are guided by readings in current science education literature, and throughout the semester students are asked to develop new course material based on the pedagogical frameworks discussed.

Folding and stability of the isolated Greek key domains of the long-lived human lens proteins gammaD-crystallin and gammaS-crystallin.

The transparency of the eye lens depends on the high solubility and stability of the lens crystallin proteins. The monomeric gamma-crystallins and oligomeric beta-crystallins have paired homologous double Greek key domains, presumably evolved through gene duplication and fusion. Prior investigation of the refolding of human gammaD-crystallin revealed that the C-terminal domain folds first and nucleates the folding of the N-terminal domain.

Interdomain side-chain interactions in human gammaD crystallin influencing folding and stability.

Human gammaD crystallin (HgammaD-Crys) is a two domain, beta-sheet eye lens protein that must remain soluble throughout life for lens transparency. Single amino acid substitutions of HgammaD-Crys are associated with juvenile-onset cataracts. Features of the interface between the two domains conserved among gamma-crystallins are a central six-residue hydrophobic cluster, and two pairs of interacting residues flanking the cluster.

Contributions of hydrophobic domain interface interactions to the folding and stability of human gammaD-crystallin.

Human gammaD-crystallin (HgammaD-Crys) is a monomeric eye lens protein composed of two highly homologous beta-sheet domains. The domains interact through interdomain side chain contacts forming two structurally distinct regions, a central hydrophobic cluster and peripheral residues. The hydrophobic cluster contains Met43, Phe56, and Ile81 from the N-terminal domain (N-td) and Val132, Leu145, and Val170 from the C-terminal domain (C-td).

Probing folding and fluorescence quenching in human gammaD crystallin Greek key domains using triple tryptophan mutant proteins.

Human gammaD crystallin (HgammaD-Crys), a major component of the human eye lens, is a 173-residue, primarily beta-sheet protein, associated with juvenile and mature-onset cataracts. HgammaD-Crys has four tryptophans, with two in each of the homologous Greek key domains, which are conserved throughout the gamma-crystallin family. HgammaD-Crys exhibits native-state fluorescence quenching, despite the absence of ligands or cofactors.

In vitro unfolding, refolding, and polymerization of human gammaD crystallin, a protein involved in cataract formation.

Human gammaD crystallin (HgammaD-Crys), a major protein of the human eye lens, is a primary component of cataracts. This 174-residue primarily beta-sheet protein is made up of four Greek keys separated into two domains. Mutations in the human gene sequence encoding HgammaD-Crys are implicated in early-onset cataracts in children, and the mutant protein expressed in Escherichia coli exhibits properties that reflect the in vivo pathology.