Analysis of the apparent biphasic axonal transport kinetics of fucosylated glycoproteins

Journal Article · Sun Jul 01 00:00:00 EDT 1984 · J. Neurosci.; (United States)

OSTI ID:6202401

Goodrum, J F; Morell, P

Following intraocular injection of (/sup 3/H)fucose, the accumulation of transported radioactivity arriving at the superior colliculus peaks within a few hours and decays with a time course of hours. Then, over a period of several days, radioactivity again accumulates at the superior colliculus and then decays with a half-life of days. Such data have been interpreted as evidence for both a group of rapidly released, rapidly transported glycoproteins (first peak) and a group of slowly released but rapidly transported glycoproteins (second peak). This supposition was investigated by studying in more detail the metabolism of some individual fucosylated proteins in both the retina and superior colliculus. It was noted that much of the radioactivity incorporated in fucosylated glycoproteins at the retina was rapidly metabolized, while the remainder of the fucosylated moieties had a metabolic half-life on the order of days. In other experiments (/sup 35/S)methionine was injected intraocularly, the metabolism in the retina was examined and a study was made of the kinetics of transport to the superior colliculus of the peptide backbone of these same individual proteins. In contrast to the two waves of accumulation of radioactivity from (/sup 3/H)fucose, accumulation of radioactivity of the peptide backbone of the same glycoproteins was monophasic. The author's explanation of these data involves the presence of two types of fucose moieties on the peptides. One group of fucose moieties is labile and is lost from the peptide backbone over a period of hours. Other fucose moieties are approximately as metabolically stable as the peptide backbones to which they are attached. The actual peptide backbones of the glycoproteins are committed to rapid transport over a period of several days.

• Research Organization: Univ. of North Carolina, Chapel Hill
• OSTI ID: 6202401
• Journal Information: J. Neurosci.; (United States), Vol. 4:7
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLUCOPROTEINS
BIOCHEMICAL REACTION KINETICS
NERVE CELLS
RADIOBIOLOGY
TRITIUM COMPOUNDS
UPTAKE
RETINA
TRACER TECHNIQUES
ANIMAL CELLS
BIOLOGY
BODY
BODY AREAS
CARBOHYDRATES
EYES
FACE
HEAD
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
REACTION KINETICS
SACCHARIDES
SENSE ORGANS
SOMATIC CELLS
551001* - Physiological Systems- Tracer Techniques