• CMI SEC-MALS system
  • CMI Jasco J815 CD instrument
  • CMI MST and ITC instruments
  • CMI SPR and BLI instruments
  • CMI Laboratory

Center for Macromolecular Interactions

Welcome to the Center for Macromolecular Interactions (CMI) in the department of Biological Chemistry and Molecular Pharmacology at Harvard Medical School.  Our mission is to enhance basic research in the HMS community by providing scientific consultation, training and access to shared biophysical instruments for the characterization and analysis of macromolecules and their complexes.

The facility currently includes instruments for Isothermal Titration Calorimetry (ITC), Surface Plasmon Resonance (SPR), Biolayer Interferometry (BLI), Differential Scanning Fluorimetry (DSF), Circular Dichroism (CD), Analytical Size Exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS), and MicroScale Thermophoresis (MST).   To learn more about technologies available, visit the CMI Instruments Page.

 

Recent CMI User Publications

Hinshaw SM, Makrantoni V, Harrison SC, Marston AL. The Kinetochore Receptor for the Cohesin Loading Complex. Cell 2017;171(1):72-84.e13.Abstract
The ring-shaped cohesin complex brings together distant DNA domains to maintain, express, and segregate the genome. Establishing specific chromosomal linkages depends on cohesin recruitment to defined loci. One such locus is the budding yeast centromere, which is a paradigm for targeted cohesin loading. The kinetochore, a multiprotein complex that connects centromeres to microtubules, drives the recruitment of high levels of cohesin to link sister chromatids together. We have exploited this system to determine the mechanism of specific cohesin recruitment. We show that phosphorylation of the Ctf19 kinetochore protein by a conserved kinase, DDK, provides a binding site for the Scc2/4 cohesin loading complex, thereby directing cohesin loading to centromeres. A similar mechanism targets cohesin to chromosomes in vertebrates. These findings represent a complete molecular description of targeted cohesin loading, a phenomenon with wide-ranging importance in chromosome segregation and, in multicellular organisms, transcription regulation.
Yu M, Amengual J, Menon A, Kamaly N, Zhou F, Xu X, Saw PE, Lee S-J, Si K, Ortega CA, Choi WI, Lee I-H, Bdour Y, Shi J, Mahmoudi M, Jon S, Fisher EA, Farokhzad OC. Targeted Nanotherapeutics Encapsulating Liver X Receptor Agonist GW3965 Enhance Antiatherogenic Effects without Adverse Effects on Hepatic Lipid Metabolism in Ldlr(-/-) Mice. Adv Healthc Mater 2017;Abstract
The pharmacological manipulation of liver X receptors (LXRs) has been an attractive therapeutic strategy for atherosclerosis treatment as they control reverse cholesterol transport and inflammatory response. This study presents the development and efficacy of nanoparticles (NPs) incorporating the synthetic LXR agonist GW3965 (GW) in targeting atherosclerotic lesions. Collagen IV (Col IV) targeting ligands are employed to functionalize the NPs to improve targeting to the atherosclerotic plaque, and formulation parameters such as the length of the polyethylene glycol (PEG) coating molecules are systematically optimized. In vitro studies indicate that the GW-encapsulated NPs upregulate the LXR target genes and downregulate proinflammatory mediator in macrophages. The Col IV-targeted NPs encapsulating GW (Col IV-GW-NPs) successfully reaches atherosclerotic lesions when administered for 5 weeks to mice with preexisting lesions, substantially reducing macrophage content (≈30%) compared to the PBS group, which is with greater efficacy versus nontargeting NPs encapsulating GW (GW-NPs) (≈18%). In addition, mice administered the Col IV-GW-NPs do not demonstrate increased hepatic lipid biosynthesis or hyperlipidemia during the treatment period, unlike mice injected with the free GW. These findings suggest a new form of LXR-based therapeutics capable of enhanced delivery of the LXR agonist to atherosclerotic lesions without altering hepatic lipid metabolism.
Arellano-Santoyo H, Geyer EA, Stokasimov E, Chen G-Y, Su X, Hancock W, Rice LM, Pellman D. A Tubulin Binding Switch Underlies Kip3/Kinesin-8 Depolymerase Activity. Dev Cell 2017;42(1):37-51.e8.Abstract
Kinesin-8 motors regulate the size of microtubule structures, using length-dependent accumulation at the plus end to preferentially disassemble long microtubules. Despite extensive study, the kinesin-8 depolymerase mechanism remains under debate. Here, we provide evidence for an alternative, tubulin curvature-sensing model of microtubule depolymerization by the budding yeast kinesin-8, Kip3. Kinesin-8/Kip3 uses ATP hydrolysis, like other kinesins, for stepping on the microtubule lattice, but at the plus end Kip3 undergoes a switch: its ATPase activity is suppressed when it binds tightly to the curved conformation of tubulin. This prolongs plus-end binding, stabilizes protofilament curvature, and ultimately promotes microtubule disassembly. The tubulin curvature-sensing model is supported by our identification of Kip3 structural elements necessary and sufficient for plus-end binding and depolymerase activity, as well as by the identification of an α-tubulin residue specifically required for the Kip3-curved tubulin interaction. Together, these findings elucidate a major regulatory mechanism controlling the size of cellular microtubule structures.
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Latest News

New Octet RED384 Software: Data Analysis HT 10.0

May 17, 2017

With the release of version 10.0 of the Octet software, ForteBio has released a fully-functional new analysis software package: Data Analysis HT 10.0, which has several new features that improve on the capabilities of original Data Analysis software. The Data Analysis HT software is the recommended choice for all new users. The legacy software, Data Analysis 10.0 is still available for use.

Read more about New Octet RED384 Software: Data Analysis HT 10.0

Demo: SEC-MALS integrated HPLC control software

December 7, 2016

Wyatt has launched HPLC management software that integrates control of Agilent chromatography systems into Astra 7.  We'll be testing this software over the next few months.  Talk to Kelly if you'd like to try it.

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