A surprising new protein superfamily containing ovalbumin, antithrombin-III, and alpha1-proteinase inhibitor

doi:10.1016/0006-291X(80)90867-0

Biochemical and Biophysical Research Communications

Volume 95, Issue 2, 31 July 1980, Pages 864-871

https://doi.org/10.1016/0006-291X(80)90867-0 Get rights and content

Abstract

A distant relationship between chicken ovalbumin and two human plasma protease inhibitors was revealed by computer analyses. We propose a new protein superfamily containing at least three families: ovalbumin (and probably gene X and gene Y proteins), antithrombin-III, and alpha₁-proteinase inhibitor. Although these families may have diverged from a common ancestor more than 500 million years ago, they may still share similarity in gene structure as well as in protein sequence.

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Citation Excerpt :
The revelation that the release of hormones from their serpin transporters in the blood is not an on-and-off process but is subtly modulated by dynamic movements of the intact reactive loop, is now opening new understandings in endocrine medicine [9,10]. Initially the recognition and naming of the serpins as a protein family focused on the protease inhibitors in human plasma [11–16]. But at the same time there was also much interest in the identification in human plasma of three non-inhibitory members of the serpin family − the hormone carriers: angiotensinogen [17], thyroxine-binding globulin [18] and corticosteroid-binding globulin [19].
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The serpins belong to the I4 family of protease inhibitors and constitute a large family of proteins found in animals, plants and different microorganisms [1]. Serpins regulate a wide range of physiological processes including blood coagulation, complement activation, inflammation, extracellular matrix remodeling, and tumor suppression [2], and their main characteristic is the inhibition of serine proteases [3,4]. Most serpins inhibit peptidases from one or several different clans [5], and in the intact serpin the reactive center constitutes an exposed mobile loop with the P1–P1′ residues acting as a bait for the target protease and responsible for defining their primary peptidase inhibitory specificity [6–8].
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A surprising new protein superfamily containing ovalbumin, antithrombin-III, and alpha1-proteinase inhibitor

Abstract

Nature

Nature

Nature

Biochem. Biophys. Res. Commun

J. Biochem

Arch. Biochem. Biophys

A surprising new protein superfamily containing ovalbumin, antithrombin-III, and alpha₁-proteinase inhibitor