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Kenneth Mills


Chemistry Department
Ph.D., Harvard University


Fields: Biochemistry


Office Phone: 508-793-3380
Office: Haberlin 337
Lab: Smith Laboratories 367
PO Box: C
Office Hours:




Research Summary

Lab Members

Lab Alumni



Lab photos


Research Summary

Our lab studies protein splicing and the enzymology of extreme thermophiles.

Protein splicing is a post-translational modification. It involves the self-catalyzed excision of an intervening polypeptide sequence, the intein, concomitant to the ligation of the flanking polypeptides, the exteins, via a native peptide bond.

Below is a schematic of the protein splicing process:

We are interested in

a) The means by which non-canonical inteins facilitate the individual steps of protein splicing.

b) The means by which inteins coordinate the steps of splicing.

c) The role that inteins play in the control of extein function.

d) Comparisons of the catalytic strategies of enzymes from thermophiles and other extremophiles and their mesophilic equivalents.

Below is the standard chemical mechanism of protein splicing:



External Grants
2019-2022      National Institutes of Health, NIGMS, R15: "Conditional Protein Splicing of inteins from extreme thermophiles and halophiles: Structure, Mechanism, and Function."
2015-2019      National Science Foundation, RUI: "RUI: The Catalysis of Protein Splicing and the Structure and Stability of Thermophilic Inteins: An Integrated Research and Education Program"
2015                Research Corporation Cottrell Scholar
2013-2016      National Science Foundation, RUI: "Intein Structure and Catalysis of Protein Splicing and Hedgehog Autoprocessing: An Integrated Research and Education Program"
2010-2013      National Science Foundation, RUI: "Catalysis and coordination of the steps of protein splicing by non-canonical inteins: An integrated research and education program"
2009-2014      Henry Dreyfus Teacher-Scholar Award
2009                ASBMB-UAN Outreach Award
2005-2010      National Science Foundation, CAREER grant, “CAREER: Alternative Mechanisms of HINT domain autoprocessing: An integrated undergraduate research and education program”
2003-2005      National Science Foundation, Major Research Instrumentation, “Acquisition of Protein Purification and Analysis Equipment to Enhance Biochemical Research and Education at the College of the Holy Cross” 
2003-2005      Research Corporation, Cottrell College Science Award, “The Mechanism and Molecular Evolution of Hedgehog Proteins and Related Auto-Processing Domains”
2002-2004      Petroleum Research Fund (American Chemical Society), Type GB, “The Mechanism of Protein Splicing and the Molecular Evolution of Inteins.”
1997-2001      Howard Hughes Medical Institute Predoctoral Fellowship
1995-1996      Barry M. Goldwater Fellowship


(Undergraduate co-authors indicated by asterisk)

37. Robinzon, S., *Cawood, A.R., *Ruiz, M.A., Gophna, U., Altman-Price, N., and Mills, K.V. (2020) Protein Splicing Activity of the Haloferax volcanii PolB-c intein is sensitive to homing endonuclease domain mutations. Biochemistry, 59, 3359-3367.
36. *Chiarolanzio, K.C., *Pusztay, J.M., *Chavez, A., Zhao, J., Xie, J., Wang, C., and Mills, K.V. (2020) Allosteric Influence of Extremophile Hairpin Motif Mutations on the Protein Splicing Activity of a Hyperthermophilic Intein. Biochemistry, 59, 2459-2467.

35. Zhao, J., Du, Z., Wang, C., and Mills, K.V. (2020) Methods to Study the Structure and Catalytic Activity of cis-splicing Inteins. Methods Mol Biol, 2133, 55-73.
34. *Ramsoomair, C.K., *Yakely, A.E., *Urbanski, L.M., *Karanja, K., *Giaccone, Z.T., *Siegart, N.M., Wang, C., Gomez, A.V., Reitter, J.N., and Mills, K.V. (2017) Coordination of the third step of protein splicing in two cyanobacterial inteins. FEBS Letters, 591, 2147-2154.
33. Zwarycz, A.S., Fossat, M., Akanyeti, O., Lin, Z., Rosenman, D.J., Garcia, A., Royer, C.A., Mills, K.V., and Wang, C. (2017) V67L Mutation Fills Internal Cavity to Stabilize RecA Mtu Intein. Biochemistry 56, 2715-2722.
32.*Minteer, C.J., *Siegart, N.M., *Colelli, K.C., Liu, X., Linhardt, R.J., Wang, C., Gomez, A.O., Reitter, J.N., and Mills, K.V. (2017) Intein-promoted cyclization of aspartic acid flanking the intein leads to atypical C-terminal cleavage. Biochemistry 56, 1042-1050.
31. Reitter, J.N., *Cousin, C.E., *Nicastri, M.C., *Jaramillo, M.V., and Mills, K.V. (2016) Salt-dependent conditional protein splicing of an intein from Halobacterium salinarumBiochemistry 55, 1279-1282.
30. Mills, K.V. (2015) Biochemistry in an undergraduate writing-intensive first-year program: Seminar courses in drugs and bioethics. Biochemistry and Molecular Biology Education 43, 263-272.
29. Kulevich, S.E., Herrick, R.S., and Mills, K.V. (2014) A Discovery Chemistry Experiment on Buffers. Journal of Chemical Education, J. Chem. Educ. 91, 1207-1211.
28. Mills, K.V., Johnson, M.A., and Perler, F.B. (2014) Protein splicing: How inteins escape from precursor proteins. Journal of Biological Chemistry, 289, 14498-14505.
27. Topilina, N.I. and Mills, K.V. (2014) Recent advances in in vivo applications of intein-mediated protein splicing. Mobile DNA 5, 5.
26. *Nicastri, M.C., *Xega, K., Li, L., Xie, J., Wang, C., Linhardt, R.J., Reitter, J.N., and Mills, K.V. (2013) Internal Disulfide Bond Acts as a Switch for Intein Activity. Biochemistry 52, 5920-5927.
25. Mills, K.V. (2013) Self-Splicing Proteins. In: Handbook of Proteolytic Enzymes, Third Edition, Vol. 1., ed. N. Rawlings and G. Salvesen, 315-321.
24. Chen, W., Li, L., Du, Z., Liu, J., Reitter, J.N., Mills, K.V., Linhardt, R.J. and Wang, C. (2012) Intramolecular Disulfide Bond between Catalytic Cysteines in an Intein Precursor. J. Am. Chem. Soc.,134, 2500-2503.
23. Du, Z., Liu, J., Albracht, C.D., Hsu, A., Chen, W., *Marieni, M.D., *Colelli, K.M., *Williams, J.E., Reitter, J.N., Mills, K.V. and Wang, C. (2011) Structural and Mutational Studies of a Hyperthermophilic Intein from DNA Polymerase II of Pyrococcus abyssi. J. Biol. Chem. 286, 38638-38648. (Cover of Nov. 4 2011 issue.)
22. Liu, J., Du, Z., Albracht, C.D., Naidu, R.O., Mills, K.V. and Wang, C. (2011) (1)H, (13)C, and (15)N NMR assignments of the Pyrococcus abyssi DNA Polymerase II intein. Biomol. NMR Assign5, 233-235.
21. Reitter, J.N. and Mills, K.V. (2011) Canonical protein splicing of a class one intein that has a class three non-canonical sequence motif. J. Bacteriol. 193, 994-997.
20. *O’Brien, K.M., *Schufreider, A.K., *McGill, M.A., *O’Brien, K.M., Reitter, J.N. and Mills, K.V. (2010) Mechanism of protein splicing of the Pyrococcus abyssi lon protease intein. Biochem. Biophys. Res. Commun.403, 457-461.
19. *Kerrigan, A.M, *Powers, T.L, *Dorval, D.M., Reitter, J.N. and Mills, K.V. (2009) Protein Splicing of the Three Pyrococcus abyssi ribonucleotide reductase inteins. Biochem. Biophys. Res. Commun. 387, 153-157.
18. Mills, K.V., Herrick, R.S., Ditzler, M.A., Nestor, L.P., Shafer, H., and Guilmette, L.W. (2008) Introducing Undergraduate Students to Electrochemistry: A Two-Week Discovery Chemistry Experiment. J. Chem. Educ.85, 1116-1119.
17.  Herrick, R.S., Mills, K.V., and Nestor, L.P. (2008) Data Pooling in a Chemical Kinetics Experiment: The Aquation of a Series of Cobalt (III) Complexes. J. Chem. Educ. 85, 1120-1122.
16.  Mills, K.V. and Guilmette, L.W. (2007) Thermochemical Analysis of Neutralization Reactions: An Introductory Discovery Experiment. J. Chem. Educ84, 326-328.
15.  Bellin, R.M. and Mills, K.V. (2007) The Holy Cross Biochemistry Concentration: An Integrated Four-Year Program to Develop Undergraduate Research Scholars. In Developing and Sustaining a Research-Supportive Curriculum, ed K.K. Karukstis and T.E. Elgren, Council on Undergraduate Research.
14.  Mills, K.V., Connor, K.R., *Dorval, D.M., and *Lewandowski, K.T. (2006) Protein Purification via Temperature-Dependent, Intein-Mediated Cleavage from an Immobilized Metal Affinity Resin.  Anal. Biochem.356, 86-93.
13.  Mills, K.V., *Dorval, D.M., *Lewandowski, K.T. (2005) Kinetic analysis of the individual steps of protein splicing for the Pyrococcus abyssi PolII intein. J. Biol. Chem 280, 2714-2720.
12. Mills, K.V., *Gareau, J.R., and *Garcia, A.M. (2005) Low-cost modification to the Copacabana method for spreading transformation mixtures.  BioTechniques39, 188.
11. Mills, K.V., Perler, F.B. (2005) The Mechanism of Intein-Based Protein Splicing: Variations on a Theme.Protein & Peptide Letters, 12, 751-755.
10. Mills, K.V. (2005) Protein Splicing. In Encyclopedia of Molecular Cell Biology and Molecular Medicine,Second Edition, ed, RA Meyers, 241-265, Weinheim: Wiley-VCH. 
9. Mills, K.V., Paulus, H. (2005) Biochemical Mechanisms of Intein-Mediated Protein Splicing. In Nucleic Acids and Molecular Biology16 (Homing Endonucleases and Inteins), ed. M. Belfort, 231-255, Berlin: Springer Verlag.
8. Mills, K.V., *Manning, J.S., *Garcia, A.M., *Wuerdeman, L.A. (2004) Protein splicing of a Pyrococcus abyssiintein with a C-terminal glutamine.  J. Biol. Chem.279, 20685-20691.
7. Mills, K.V. (2004) Self-Splicing Proteins.  In: Handbook of Proteolytic Enzymes, Second Edition, Vol. 2., ed. AJ Barrett, 2136-2140, London: Academic Press, Elsevier Science.
6. Mills, KV.  (2003) Post-Translational Control.  In: Genetics, Vol. 3., ed. R Robinson, 178-182, New York: Macmillan Reference USA.
5. Mills, K.V., Paulus, H.  (2001) Reversible Inhibition of Protein Splicing by Zinc Ion.  J. Biol. Chem. 276, 10832-10838.
4. Lew, B.M., Mills, K.V., Paulus, H. (1999) Characteristics of Protein Splicing in trans Mediated by a Semisynthetic Split Intein. Biopolymers (Peptide Science)51, 355-362.
3. Lew, B.M., Mills, K.V., Paulus, H. (1998) Protein Splicing in Vitro with a Semisynthetic Two-Component Minimal Intein. J. Biol. Chem.273, 15887-15890.
2. Mills, K.V., Lew, B.M., Jiang, Sq, Paulus, H.  (1998) Protein splicing in trans by purified N- and C- terminal fragments of the Mycobacterium tuberculosis RecA intein. Proceedings of the National Academy of Sciences, USA95, 3543-3548.
1. Broomfield, C.A., Mills, K.V., Meier, B.M., Lockridge, O.A., and Millard, C.B.  (1998) Reaction of human butyrylcholinesterase (BchE) H117 enzymes with carbamates.  In: Structure and Function of Cholinesterases and Related Proteins, 223-226.

Lab Members

Ken Mills, Ph.D., Principal Investigator

Barbara Aikaterinidis, 2024
Beatrice Barbesino, Chemistry 2023
Angel Chavez, Chemistry 2021
Anthony D'Angelo, Chemistry 2022
Michelle Haigbea, Biology 2023

Bella Jankowski, Chemistry/Biochemistry 2021
Liam Lewis, Chemistry 2021
Thuy Nguyen, Chemistry/Sociology 2022
Kallie Poon, 2024

Lily Russo, Chemistry 2022
Mercedes Ruiz, English, 2021
Sean Tarrant, Biology/Biochemistry 2021
Diana Wall, Biology 2022
Vaish Yalala, Chemistry/Sociology 2021

Josue Alvarado, Sociology 2023
Justin Hackshaw, Economics 2022


Lab Alumni

Shirley Amunya, Fitchburg St '17, Teach for America
Alexander Bonano, Spanish '17
Sarah Cahn, Chemistry '14, Takeda Oncology
Dawilmer Castillo, Bridgewater St. '15, Masters, Brown

Alexandra Cawood, Chemistry '20
Jenny Manning Chapnick, Biology '03 
Stacy Chin, Chemistry '12, PhD, Boston U
Katie Colelli, Bio/Biochemistry '13, M.D., UVM

Hannah Comeau, Chemistry '18, Masters, Johns Hopkins
Kate Connor, Research Assistant
Owen Conroy, Biology '19
Vanessa Costa, Sociology '18, Clinical specialist  
Chris Cousin, Chemistry '16, PharmD, MCPHS
Beth (Ambrose) Dean, Chemistry '02, Physician's Assistant
Julliard del Rosario, Cornell U, '16  
Colleen Donahue, Biology '11, M.D., Tufts
Matt Drago, Bio/Biochem '07, M.D., UPenn
Lauren Duffee, Bio/Biochem '10, D.V.M., UPenn

Patrick Exconde, Chem/Biochem '19, Research Assistant MGH
Zach Giaccone, Chem/Biochem '15, Dental School, UConn
Alvin Gomez, Research Associate 
Nick Gulbrandsen, Bio Fitchburg '13 
Dan Haley, Chemistry '14, Dental School, UConn

Chinnel Hudson, Sociology '20
C.J. Janton, Bio/Biochem '18, Research Assistant Harvard Med
Mario Jaramillo, Biology '15, MD Student, Albany Med
Kevin Karanja, Chemistry '12 WSU, Science Teacher-Burncoat Middle
Adam Kerrigan, Biology '09, Cybereason
Mike Koulopoulos, Chem/Biochem '16, MD student, Wake Forest

Kate Leahy, Math '04, Research Assistant, Partners Healthcare
Katie Lewandowski, Bio/Biochem '05, Postdoc, Northwestern; PhD, Wash. U.
Josh Long, Biology 2017, CRC-Mass General
Lisa (Wuerdeman) Lucas, Chemistry '03, D.O., U. New England

Abby Lynch, Biology/Biochem '19, CRC
Michelle Marieni, Biology '11, M.D., Creighton
Melissa McGill, Bio/Biochem' 08, M.S., Michigan; Pfizer, Senior Associate Scientist
Jackie (Gareau) Merrick, Chem/Biochem '04, Ph.D, Cornell-Weill; HS teacher
Ralph Millilo, Bio/Biochem '03, M.D., SUNY Upstate
Chris Minteer, Chem/Biochem '17, PhD student, Yale
Adam Nadelson, Biology '10, M.D., UMass
Michael Nicastri, Chem/Biochem '13, PhD, UPenn
Kathryn O'Brien, Chem/Biochem '08, PhD, Cornell-Weill
Kevin O'Brien, Bio/Biochem '11, PhD, U. Georgia, PD UMass Med
Isabelle Pierre, UMass Dartmouth '15, Research Assist. - BWH
Jen Pusztay, Chem/Biochem '13, D.O.
Tim Quinn, Chem/Biochem '13, M.D.-Georgetown

Christian Ramsoomair, Chem/Biochem '18
Deirdre Reidy, Biology '18, MD student, UConn
Julie Reitter, Ph.D., Research Associate 
George Savidis, Bio/Biochem '12, Research Assistant, UMass
Annie Schufreider, Chemistry '09, M.D., Loyola Chicago
Lisa (Garcia) Seals, Biology '03, Middle School Teacher
Nikki Siegart, Bio/Biochem '15, MD Student SUNY Downstate
Taryn (Powers) Surabian, Biology '07, Ursuline Academy

Nhi Tran, UMass Amherst 2019
Pat Twomey, Chem/Biochem '02, M.D., Georgetown
Laura Urbanski , Chem/Biochem '13, MD/PhD program, UConn
Deirdre (Dorval) Wells, Biology '06, J.D., Harvard Law School

Amanda Wibben, Biology '19, Fulbright India, Theology/Ethics grad student Harvard
Jennie Williams, Chemistry '13, Teacher, Chapel Hill-Chauncy Hall
Jen Winslow, Biology '09, DO, University of New England
Kristina Xega, Chemistry '11, Takeda Oncology

Anthony Yakely, Chem/Biochem '16, JVC Northwest, MPH Yale
Dan York, Bio/Biochem '10, MD, Texas Tech
Wanlin Zhang, Chem/Biochem '17, Dental student