TABLE 1.

P-2 column fractions (III and IV) contain a β-1,2-mannotriose and inhibit MAb C3.1-dependent agglutination of mannan-coated latex beads^a

Expt	Fraction	Agglutinationb at fraction concn (μg/ml) of:
		2,000	1,800	1,600	1,400	1,200	1,000	500	250	200	20	2
1A	I, II, and V–VII	NI								NI	NI	NI
	III	I								NI	NI	NI
	IV	I								NI	NI	NI
	Acid-stable PMCc	NI								NI	NI	NI
	Raffinose (triose control)	NI								NI	NI	NI
	Stachyose (tetraose control)	NI								NI	NI	NI
1B	III	I	I	I	I	NI	NI	NI	NI
	IV	I	I	I	I	NI	NI	NI	NI
	Mannan (whole)	I	I	I	NI	NI	NI	NI	NI
2	I, II, and V–VII	NI					NI	NI	NI	NI	NI	NI
	III	I					I	I	NI	NI	NI	NI
	IV	I					I	I	NI	NI	NI	NI
	Acid-stable PMC	NI					NI	NI	NI	NI	NI	NI

^aOligomannosyl residues that were released from the PMC as a result of acid hydrolysis (acid-labile components) were separated by size on a P-2 (acrylamide gel) column. Each fraction designation denotes the number of mannose units as determined from mass spectral analysis and control elution profiles (13). For two or more mannose units per fraction, the mannose units are β-1,2 linked as determined by two-dimensional nuclear magnetic resonance analysis (13). Each fraction (10 μl) at the indicated concentrations was mixed with 10 μl of MAb C3.1, and then a 10-μl volume of mannan-coated latex beads was added, mixed, and observed for agglutination of the beads. In experiments 1A and 1B, the mannan-latex agglutination titer of MAb C3.1 was 40; for experiment 2, the titer was 5. 

^bNI, not inhibited; I, inhibited. 

^cThe part of the PMC that is devoid of the β-1,2-linked oligomannosyl chains that are bonded to the acid-stable part of the complex via phosphodiester bonds.