PMID- 3907306
OWN - NLM
STAT- MEDLINE
DCOM- 19860107
LR  - 20191022
IS  - 0065-2571 (Print)
IS  - 0065-2571 (Linking)
VI  - 23
DP  - 1985
TI  - Protein O-carboxylmethylation in relation to male gamete production and function.
PG  - 389-416
AB  - Protein O-carboxylmethyltransferase (PCM) activity of differentiating male germ 
      cells in the testis and of spermatozoa is strikingly high. PCM catalyzes the 
      methylesterification by S-adenosylmethionine of dicarboxylic amino acid residues 
      in proteins. PCM appears to be the only type of protein methyltransferase present 
      in mature spermatozoa. Mammalian sperms contain considerable amounts of 
      S-adenosylmethionine and can apparently synthesize this nucleoside from 
      L-methionine and ATP. Spermatozoa are rich in S-adenosylhomocysteine hydrolase. 
      The characteristics of this enzyme in testicular germ cells and in sperms are 
      very similar to those in other mammalian tissues; the very sub-stoichiometric 
      extent of methylation of various pure protein substrates, and the rapid 
      spontaneous hydrolysis of the protein methyl ester products at physiological and 
      especially higher pH values, are particularly remarkable. From studies on 
      processes related to protein O-carboxylmethylation in rat spermatozoa from 
      different regions of the epididymis, and in ejaculated spermatozoa from normal 
      and infertile men, unequivocal evidence could not be obtained for hypotheses of 
      other investigators that PCM-catalyzed reactions are of regulatory importance for 
      the acquisition of a potentiality for motility in sperms during their transit and 
      maturation in the epididymis, or for the locomotion of ejaculated sperms. The 
      findings are discussed in the light of the recent hypothesis of S. Clarke that 
      PCM catalyzes methylesterification of D-aspartyl residues that accumulate in 
      certain proteins as a result of slow spontaneous racemization of L-aspartyl 
      residues, and that the methyl esterification of D-aspartyl residues may be 
      related to disposal or repair of proteins damaged in this fashion.
FAU - Williams-Ashman, H G
AU  - Williams-Ashman HG
FAU - Hatch, R
AU  - Hatch R
FAU - Harvey, S E
AU  - Harvey SE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
PL  - England
TA  - Adv Enzyme Regul
JT  - Advances in enzyme regulation
JID - 0044263
RN  - 0 (Proteins)
RN  - 7LP2MPO46S (S-Adenosylmethionine)
RN  - EC 2.1.1.- (Protein O-Methyltransferase)
SB  - IM
MH  - Animals
MH  - Cell Differentiation
MH  - Humans
MH  - Male
MH  - Methylation
MH  - Protein Biosynthesis
MH  - Protein O-Methyltransferase/metabolism
MH  - Proteins/*metabolism
MH  - Rats
MH  - S-Adenosylmethionine/metabolism
MH  - Sperm Maturation
MH  - Sperm Motility
MH  - Sperm Transport
MH  - Spermatozoa/enzymology/*metabolism
MH  - Testis/enzymology
RF  - 81
EDAT- 1985/01/01 00:00
MHDA- 1985/01/01 00:01
CRDT- 1985/01/01 00:00
PHST- 1985/01/01 00:00 [pubmed]
PHST- 1985/01/01 00:01 [medline]
PHST- 1985/01/01 00:00 [entrez]
AID - 10.1016/0065-2571(85)90058-5 [doi]
PST - ppublish
SO  - Adv Enzyme Regul. 1985;23:389-416. doi: 10.1016/0065-2571(85)90058-5.