Characterization of sialoglycoproteins of rat epididymal fluid and spermatozoa by periodate tritiated borohydride

Abstract

Sialoglycoproteins of rat epididymal fluid and spermatozoa were radio-labelled by the NaIO4/KB3H4method. At least 10 sialoglycoproteins of the epididymal fluids could be consistently demonstrated by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. Two major ones (M(r) 21 000 and 66 000) were present in the fluids of the caput and cauda epididymidis. Two (M(r) 28 000 and 40 000) were found only in the former and two (M(r) 32 000 and 42 000) only in the latter. There were at least 11 sialoglycoproteins bound to the epididymal spermatozoa. During epididymal transport, 8 sialoglycoproteins on the spermatozoa decreased, one (M(r) 48 000) remained constant and one (M(r) 31 000) increased in amount. During sperm maturation, some sperm-bound sialoglycoproteins, especially 3 of small molecular weights, became more resistant to the treatments with neuraminidase, trypsin and Triton X-100.