• Center for Macromolecular Interactions
  • CMI Laboratory

    Welcome to the CMI

    An HMS core for the characterization of macromolecules and their interactions.

  • CMI SEC-MALS system

    CMI SEC-MALS system

    Multi-Angle Light Scattering and Dynamic Light Scattering are used to measure the molar mass and hydrodynamic radius.

  • CMI SPR and BLI instruments

    CMI SPR and BLI Instruments

    Surface Plasmon Resonance and Biolayer Interferometry are used to measure binding kinetics.

  • CMI MST and ITC instruments

    CMI MST and ITC Instruments

    Isothermal Titration Calorimetry and Microscale Thermophoresis measuring binding in solution.

Coronavirus Update

The CMI is in Phase 2B Re-Entry.  The CMI COVID-19 Plan summarizes the changes implemented at CMI to maintain social distancing, enhance safety and accomodate as many users as possible. 

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)Light Scattering: size-exclusion chromatography with multi-angle light scattering (SEC-MALS) and Dynamic Light Scattering (DLS), and MicroScale Thermophoresis (MST)

Recent User Publications

Lowey B, Whiteley AT, Keszei AFA, Morehouse BR, Mathews IT, Antine SP, Cabrera VJ, Kashin D, Niemann P, Jain M, Schwede F, Mekalanos JJ, Shao S, Lee ASY, Kranzusch PJ. CBASS Immunity Uses CARF-Related Effectors to Sense 3'-5'- and 2'-5'-Linked Cyclic Oligonucleotide Signals and Protect Bacteria from Phage Infection. Cell 2020;Abstract
cGAS/DncV-like nucleotidyltransferase (CD-NTase) enzymes are immune sensors that synthesize nucleotide second messengers and initiate antiviral responses in bacterial and animal cells. Here, we discover Enterobacter cloacae CD-NTase-associated protein 4 (Cap4) as a founding member of a diverse family of >2,000 bacterial receptors that respond to CD-NTase signals. Structures of Cap4 reveal a promiscuous DNA endonuclease domain activated through ligand-induced oligomerization. Oligonucleotide recognition occurs through an appended SAVED domain that is an unexpected fusion of two CRISPR-associated Rossman fold (CARF) subunits co-opted from type III CRISPR immunity. Like a lock and key, SAVED effectors exquisitely discriminate 2'-5'- and 3'-5'-linked bacterial cyclic oligonucleotide signals and enable specific recognition of at least 180 potential nucleotide second messenger species. Our results reveal SAVED CARF family proteins as major nucleotide second messenger receptors in CBASS and CRISPR immune defense and extend the importance of linkage specificity beyond mammalian cGAS-STING signaling.
Patsoukis N, Duke-Cohan JS, Chaudhri A, Aksoylar H-I, Wang Q, Council A, Berg A, Freeman GJ, Boussiotis VA. Interaction of SHP-2 SH2 domains with PD-1 ITSM induces PD-1 dimerization and SHP-2 activation. Commun Biol 2020;3(1):128.Abstract
Programmed cell death-1 (PD-1) inhibits T cell responses. This function relies on interaction with SHP-2. PD-1 has one immunoreceptor tyrosine-based inhibitory motif (ITIM) at Y223 and one immunoreceptor tyrosine-based switch motif (ITSM) at Y248. Only ITSM-Y248 is indispensable for PD-1-mediated inhibitory function but how SHP-2 enzymatic activation is mechanistically regulated by one PD-1 phosphotyrosine remains a puzzle. We found that after PD-1 phosphorylation, SHP-2 can bridge phosphorylated ITSM-Y248 residues on two PD-1 molecules via its amino terminal (N)-SH2 and carboxyterminal (C)-SH2 domains forming a PD-1: PD-1 dimer in live cells. The biophysical ability of SHP-2 to interact with two ITSM-pY248 residues was documented by isothermal titration calorimetry. SHP-2 interaction with two ITSM-pY248 phosphopeptides induced robust enzymatic activation. Our results unravel a mechanism of PD-1: SHP-2 interaction that depends only on ITSM-Y248 and explain how a single docking site within the PD-1 cytoplasmic tail can activate SHP-2 and PD-1-mediated inhibitory function.
Gorgulla C, Boeszoermenyi A, Wang Z-F, Fischer PD, Coote P, Padmanabha Das KM, Malets YS, Radchenko DS, Moroz YS, Scott DA, Fackeldey K, Hoffmann M, Iavniuk I, Wagner G, Arthanari H. An open-source drug discovery platform enables ultra-large virtual screens. Nature 2020;Abstract
On average, an approved drug today costs $2-3 billion and takes over ten years to develop. In part, this is due to expensive and time-consuming wet-lab experiments, poor initial hit compounds, and the high attrition rates in the (pre-)clinical phases. Structure-based virtual screening (SBVS) has the potential to mitigate these problems. With SBVS, the quality of the hits improves with the number of compounds screened. However, despite the fact that large compound databases exist, the ability to carry out large-scale SBVSs on computer clusters in an accessible, efficient, and flexible manner has remained elusive. Here we designed VirtualFlow, a highly automated and versatile open-source platform with perfect scaling behaviour that is able to prepare and efficiently screen ultra-large ligand libraries of compounds. VirtualFlow is able to use a variety of the most powerful docking programs. Using VirtualFlow, we have prepared the largest and freely available ready-to-dock ligand library available, with over 1.4 billion commercially available molecules. To demonstrate the power of VirtualFlow, we screened over 1 billion compounds and discovered a small molecule inhibitor (iKeap1) that engages KEAP1 with nanomolar affinity (K = 114 nM) and disrupts the interaction between KEAP1 and the transcription factor NRF2. We also identified a set of structurally diverse molecules that bind to KEAP1 with submicromolar affinity. This illustrates the potential of VirtualFlow to access vast regions of the chemical space and identify binders with high affinity for target proteins.
Patnaik D, Pao P-C, Zhao W-N, Silva CM, Hylton NK, Chindavong PS, Pan L, Tsai L-H, Haggarty SJ. Exifone is a Potent HDAC1 Activator with Neuroprotective Activity in Human Neuronal Models of Neurodegeneration. bioRxiv 2020;27(2):2020.03.02.973636.Abstract
Genomic instability caused by a deficiency in the DNA damage response and repair has been linked to age-related cognitive decline and neurodegenerative disease. Preventing this loss of genomic integrity that ultimately leads to neuronal death may provide a broadly effective strategy to protect against multiple potential genotoxic stressors. Recently, the zinc-dependent, class I histone deacetylase HDAC1 has been identified as a critical protein for protecting neurons from deleterious effects mainly caused by double-strand DNA breaks in Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). Translating these observations to a novel neuroprotective therapy for AD, ALS or FTD will benefit from the identification of small molecules capable of selectively increasing the deacetylase activity of HDAC1 over other structurally similar class I HDACs. Here, we demonstrate that exifone, a drug previously shown to be effective in treating cognitive decline associated with AD and Parkinson’s disease, the molecular mechanism of which has remained poorly understood, potently activates the deacetylase activity of HDAC1 and provides protection against genotoxic stress. We show that exifone acts as a mixed, non-essential activator of HDAC1 that is capable of binding to both free and substrate-bound enzyme resulting in an increased relative maximal rate of HDAC1-catalyzed deacetylation. Selectivity profiling and estimation of kinetic parameters using biolayer interferometry suggest HDAC1 is a preferential target compared to other class I HDACs and CDK5. Treatment of human induced pluripotent stem cell (iPSC)-derived neuronal cells resulted in a decrease of histone acetylation, consistent with an intracellular mechanism of deacetylase activation. Moreover, using tauopathy patient-derived iPSC neuronal models subject to oxidative stress through mitochondrial inhibition exifone treatment was neuroprotective. Taken together, these findings reveal exifone as a potent activator of HDAC1-mediated deacetylation, thereby offering a lead for novel therapeutic development aiming to protect genomic integrity in the context of neurodegeneration and aging.
Bernard-Gauthier V, Mossine AV, Knight A, Patnaik D, Zhao W-N, Cheng C, Krishnan HS, Xuan LL, Chindavong PS, Reis SA, Chen JM, Shao X, Stauff J, Arteaga J, Sherman P, Salem N, Bonsall D, Amaral B, Varlow C, Wells L, Martarello L, Patel S, Liang SH, Kurumbail RG, Haggarty SJ, Scott PJH, Vasdev N. Structural Basis for Achieving GSK-3β Inhibition with High Potency, Selectivity, and Brain Exposure for Positron Emission Tomography Imaging and Drug Discovery. J Med Chem 2019;62(21):9600-9617.Abstract
Using structure-guided design, several cell based assays, and microdosed positron emission tomography (PET) imaging, we identified a series of highly potent, selective, and brain-penetrant oxazole-4-carboxamide-based inhibitors of glycogen synthase kinase-3 (GSK-3). An isotopologue of our first-generation lead, [H]PF-367, demonstrates selective and specific target engagement in vitro, irrespective of the activation state. We discovered substantial ubiquitous GSK-3-specific radioligand binding in Tg2576 Alzheimer's disease (AD), suggesting application for these compounds in AD diagnosis and identified [C]OCM-44 as our lead GSK-3 radiotracer, with optimized brain uptake by PET imaging in nonhuman primates. GSK-3β-isozyme selectivity was assessed to reveal OCM-51, the most potent (IC = 0.030 nM) and selective (>10-fold GSK-3β/GSK-3α) GSK-3β inhibitor known to date. Inhibition of CRMP2 and tau phosphorylation, as well as favorable therapeutic window against WNT/β-catenin signaling activation, was observed in cells.

CMI News

New PPMS System

November 1, 2020

The CMI has migrated to a new shared instance of our PPMS booking system.  This is a major overhaul of our system, so we may encounter some issues during the transition phase. Don’t hesitate to reach out if you have any problems. 

All users will need an active CMI Instrument Access Project.

  • In the new system, you will need to select this project when you make instrument reservations or order consumables.
  • If you currently have instrument rights, then I have already created a project for you in the new system.
  • New users will need to request a project in the new PPMS system before requesting training or gaining instrument access.

CMI Getting Started Guides updated

May 22, 2020
Instrument getting started guides have all been updated with new content and a new look. Get the latest version in instrument pages in Technologies.  Please let us know if you find any problems.