Life Sciences ~Qo. 11, pp . 621-623, 1962 " United States .-
Pergemon Press, Inc.
Printed in the
THE DISTRIBUTION OF AVIDIN Peter D . Jones and Michael H. Briggs*' Victoria University of Wellington New Zealand (Received 8 October 1960 AVIDIN is s protein first detected in the white of hen's
It has been
crystallized from this source and shown to be a basic protein of molecular weight ca . 66,000 .2
Avidin forms a stable complex with biotin :
occurring both in vitro and in vivo on the feeding of raw egg white to an animal .3 For this reason the raw white of hen's egg is toxic to a wide range. of animals .
Previous workers$' 9 have shown that avidin-like proteins occur in the egg whites of several other avian species .
D.ius Hertz and Sebrella reported the
following avidin concentrations for dried egg whites : duck 7.1, goose 8.0 .
hen 11 .5, turkey 16 .2,
~ese results are expressed in avidin units per gram .
unit of avidin activity is defined as that amount of avidin that will combine with one microgram of pure d-biotin . ~eae findings indicate that avidin-like proteins :my be a common constituent of bird egg-whites .
We have consequently examined for avidin, specimens of egg
whites from species representing e11 the major avian families . 7~e assay method used Lactobacillus arabinosus 17-5, obtained Pram the American ~rpe Culture Collection, as test organism . lO medium for biotin assay.
It was graven on "Difco"
Avidin activity was determined by measuring bacterial
growth in tubes containing 1.0 ml of egg white and varying amounts of d-biotin . Results of these experiments are given in Table 1 .
It is apparent that
avidin proteins are present in all ; with the possible exception of the herring
Present address :
Jet Propulsion Laboratory, California Institute of Zlechnology, Pasadena, California, U.S .A . 621
~ DIS~IBtfrION OF AV.mIId
Avidin Content of Egg Whites
Avidin content (units per gram dried weight)
Melopsittacus undulatus Psittacidae
During a search for avidin-like proteins, Woolley and Longsworth
6 .8 11
that protamiae, a crystalline po].ypeptide of salmon sperm, possessed weak avidin activity :
approximately 0.1 - 0.2 per cent of the activity of pure avidin oa a
dry weight basis .
We have confirmed this finding and have also assayed fresh
bull sperm for biotin-binding capacity.
We find that this material possesses
0.02 units of avidin activity per gram fresh weight .
We were unable to detect
avidia activity is dried sperm. Zhe discovery of biotin-binding proteins in egg whites and in sperm Pram quite different groups of saimals suggests that gvidia proteins may be very
THE DISTRIBUTIOA OF AVIDIN
No . 11
irl.dely distributed in the animal kingdom, and moreover may play some fundamental role in the physiology of reproduction . Acknowle nt - We are most grateful to Professor C. G. Sibley of Cornell University for t e generous gift of egg ~rhite samples . References 1.
R. E. EAKIN, E . E. SftELL and R. J. WILLIAMS, J. Biol . ~em. 136, 201 (1940) ; 535 (1941) .
H. ERAII~TI~-CONRAT et al ., Arch . Biochem. Biophys . ~, 80 (1952) .
M. A. BOAS, Biochem. J. 21, 712 (l927) .
S. G . SMI'~, Science 100, 389 (194~+)"
H. RAUCH and W. B. RUtTIIiG, Experientia 14, 3~ (1958) "
P. S. SARMA, Indian J. Med. Res. ~, 149 (1944) .
W. P . LEHRER, A. C.
R . HERTZ and W. H. SERRELL, Science ~6, 257 (1942),
R . E. FEQ~7C et al ., J. Biol . Gliem. 2~, 2307 (1960) .
L. D. WRIGHT and H. R. SKEGGS, Proc . Soc. Exp. Biol . Med. ~, 92 (l944) .
D. W. WOOLLEY e~nd L. G. IAHGSWOiRTH, J. Biol . (~em . 142, 285 (1942) .
and P. R . A9DORE, J. ftutr . 47, 203 (1952) .