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BIOPHYSICAL SOCIETY NEWSLETTER
18
AUGUST
2016
Obituary
Bill Klug
Quiet Adventurer, Transcendent Human
(1976–2016)
It is with heavy hearts that we report the terribly
premature and tragic death of
Bill Klug
, a noted
practitioner of computational mechanics whose
interests centered on biophysical phenomena in
contexts ranging from viruses to the human heart.
It has been said that “life well lived is long,” but
Bill Klug’s incredibly well-lived 39 years were
far too short by any measure, regardless of how
extraordinarily well lived they were.
Bill was a California boy; it was his home from his
childhood years through college, graduate school,
and where he was now raising his own beautiful
young family. As an undergraduate at Westmont
College in Santa Barbara, and as a master’s stu-
dent at UCLA, Bill had already established two of
the great loves of his life, his wife
Mary Elise
and
the use of mathematics as a way to understand and
engineer the world around him. As a graduate
student at the California Institute of Technology,
where he studied with
Michael Ortiz
, Bill began
his first forays into the power of computational
mechanics as a way of studying the living world.
Bill’s thesis work was inspired by stunningly beau-
tiful single-molecule experiments that measured
how force builds up inside of viruses as a result of
their packaged genomes. Bill took a clever con-
tinuum mechanics approach for representing the
structure of the packaged DNA permitting him to
compute its stored energy.
One of Bill’s most impressive attributes — and
the basis of how he lived his life in general — is
that he was a quiet adventurer. Upon landing a
job at UCLA as an assistant professor in mechani-
cal engineering, nothing would have been easier
than to settle into a productive and even exciting
career studying traditional mechanics problems.
Instead, both in his teaching and research, he set
out to redefine what it means to be a computa-
tional mechanician, setting his sights on a quan-
titative understanding of the mechanics of living
systems, from sub-cellular scales to the scale of
human organs such as the heart.
Bill’s research focused on several areas of central
importance to biophysics, where it was clear that
the principles of mechanics played a critical part
in the underlying biological phenomena. Inspired
by his thesis work, Bill established many excit-
ing collaborations with experimental groups that
examined the mechanical response of viral capsids
to mechanical stimuli, such as those imposed us-
ing the atomic force microscope (AFM). In these
experiments, an AFM tip is used to push on the
virus, and Bill and his many collaborators used
a combination of analytical thinking and finite-
element models to study the mechanical response
of the capsids, making detailed comparisons with
the results of experimental studies. More recently,
Bill pioneered new numerical methods for the
application of non-linear elasticity theory to study
problems such as the maturation of viral capsids.
This led to a better understanding of viral capsids
as macromolecular machines that cleverly manage
built-in elastic stress.
The mechanics of lipid bilayer membranes was
another area that enticed Bill. Here too—whether
in the context of optical tweezer experiments on
membrane tethers or the study of the ordered
arrays formed by membrane proteins—he showed
how the finite element method could be used as a
powerful window onto membrane mechanics. He
was also intrigued by networks of cytoskeletal fila-
ments and made important contributions to our
understanding of the mechanics of networks of
stiff protein filaments, with implications for how
cells generate and respond to force. One of Bill’s
recent growing enthusiasms was the modeling of
the human heart. What captured Bill’s imagina-
tion in this problem was the interaction between
the complex geometry of the heart, its mechanical
response, and how these different aspects of the
heart dictate cardiac electrophysiology.
As all of these examples show, Bill’s mind traveled
adventurously across biological phenomena and
the length scales at which they occur. Further, his
talent and knowledge in attacking hard problems
with elegant and transparent numerical methods
coupled with his enthusiastic
Bill Klug