Purification and partial amino acid sequences of two distinct albumins from turtle plasma.
Two putative albumins, denoted Alb-1 (apparent molecular mass of 67 kDa) and Alb-2 (68 kDa), were purified from plasma of the emydid turtle (Trachemys scripta). Concentrations in serum or plasma were determined by radioimmunoassay using 125I-labeled Alb-1. In juvenile turtles (less than 2 years of age), serum concentrations of Alb-1 and Alb-2 were 2.72 +/- 0.23 mg/ml and 1.68 +/- 0.22 mg/ml, respectively, while concentrations in plasma pooled from adult turtles were 4.2 mg/ml and 2.6 mg/ml, respectively. The two albumins are immunologically distinct from one another as determined by both radioimmunoassay with 125I-labeled Alb-1 and Western blot analysis with antichicken albumin antiserum. Determination of the amino acid compositions of Alb-1 and Alb-2, and of albumin purified from plasma of the common snapping turtle (Chelydra serpentina), suggested that Alb-1 is more similar to albumins of other animals than is Alb-2. This was also indicated by Western blot analysis and by determining the N-terminal amino acid sequences of Alb-1 (40 residues) and Alb-2 (15 residues). Thus, it appears that two distinct forms of albumin are synthesized by T. scripta, possibly as a result of gene duplication and divergence.
Brown
M A
MA
Biochemistry and Genetics Research Unit, School of Biological Sciences, Victoria University of Wellington, New Zealand. mabrown@unixg.ubc.ca
Chambers
G K
GK
Licht
P
P
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D015153:Blotting, Western; D008969:Molecular Sequence Data; D011863:Radioimmunoassay; D017386:Sequence Homology, Amino Acid; D012709:Serum Albumin / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification*; D014426:Turtles; D014714:Vertebrates
D000596:Amino Acids; D012709:Serum Albumin