Proteomic studies of isoforms of the P25 component of Bombyx mori fibroin.
It is recognized that P25 is one of three polypeptide components of the fibroin synthesized in the larval silk gland (SG) of silkworm, having two glycosylated isoforms. In the present study, however, eight P25 isoforms were separated by proteomics, including two-dimensional gel electrophoresis of whole SG proteins, and were identified by the peptide mass fingerprinting method. Four of the eight isoforms were identified as Bombyx mandarina P25s, although the SG of Bombyx mori has never been considered to contain the P25 from B. mandarina. It is suggested that this diversity of P25 isoforms depends on phosphorylation modification in addition to glycosylation.
Zhang
Pingbo
P
Institute of Genetic Resources, Kyushu University, Fukuoka, Japan.
Yamamoto
Kohji
K
Aso
Yoichi
Y
Banno
Yutaka
Y
Sakano
Daisuke
D
Wang
Yongqiang
Y
Fujii
Hiroshi
H
D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D005349:Fibroins / Q000737:chemistry / Q000302:isolation & purification*; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification*; D006031:Glycosylation; D013058:Mass Spectrometry; D010766:Phosphorylation; D020033:Protein Isoforms / Q000302:isolation & purification; D011499:Protein Processing, Post-Translational; D040901:Proteomics
D006023:Glycoproteins; D020033:Protein Isoforms; C418613:fhx protein, Bombyx mori; D005349:Fibroins