Browsing by Author "Liao, Ming-Huei"

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A unique tetrameric structure of deer plasma haptoglobin - an evolutionary advantage in the Hp 2-2 phenotype with homogeneous structure
(2008-03-01)
Lai, I. H.
;
Lin, Kung-Yu
;
Larsson, Mikael
;
Yang, Ming Chi
;
Shiau, Chuen-Huei
Similar to blood types, human plasma haptoglobin (Hp) is classified into three phenotypes: Hp 1-1, 2-1 and 2-2. They are genetically inherited from two alleles Hp 1 and Hp 2 (represented in bold), but only the Hp 1-1 phenotype is found in almost all animal species. The Hp 2-2 protein consists of complicated large polymers cross-linked by alpha 2-beta subunits or (alpha 2-beta)(n) (where n >= 3, up to 12 or more), and is associated with the risk of the development of diabetic, cardiovascular and inflammatory diseases. In the present study, we found that deer plasma Hp mimics human Hp 2, containing a tandem repeat over the alpha-chain based on our cloned cDNA sequence. Interestingly, the isolated deer Hp is homogeneous and tetrameric, i.e. (alpha-beta)(4), although the locations of -SH groups (responsible for the formation of polymers) are exactly identical to that of human. Denaturation of deer Hp using 6 M urea under reducing conditions (143 mM beta-mercaptoethanol), followed by renaturation, sustained the formation of (alpha-beta)(4), suggesting that the Hp tetramers are not randomly assembled. Interestingly, an alpha-chain monoclonal antibody (W1), known to recognize both human and deer alpha-chains, only binds to intact human Hp polymers, but not to deer Hp tetramers. This implies that the epitope of the deer alpha-chain is no longer exposed on the surface when Hp tetramers are formed. We propose that steric hindrance plays a major role in determining the polymeric formation in human and deer polymers. Phylogenetic and immunochemical analyses revealed that the Hp 2 allele of deer might have arisen at least 25 million years ago. A mechanism involved in forming Hp tetramers is proposed and discussed, and the possibility is raised that the evolved tetrameric structure of deer Hp might confer a physiological advantage.
Association of Human Q Fever with Animal Husbandry, Taiwan, 2004-2012
(2015-12-01)
Lai, Chung-Hsu
;
Chang, Lin-Li
;
Lin, Jiun-Nong
;
Liao, Ming-Huei
;
Liu, Shyh-Shyan
In Taiwan, Q fever cases in humans began increasing in 2004 and peaked in 2007 but dramatically declined in 2008 and 2011. Cases were significantly correlated with the number of goats. The decline might be associated with the collateral effects of measures to control goat pox in 2008 and 2010.